Printing is the process and result of reproducing text and images , usually with ink on paper . It is possible to print on a wide variety of materials, being necessary to use different printing systems in each case. It can be done domestically, by hand, commercially or on a large scale, and is an essential part of book publishing and all kinds of printed publications . New 3D printing techniques offer new applications in various fields.

Throughout history there have been different printing systems, some such as serigraphy or lithography have been adapted to the evolution of the technique and still endure, others such as xylography that had been widely used have lost their validity and today are only used for the reproduction of works of art. Until the advent of digital printing, all methods have had as a common feature the use of an inked matrix that allowed it to be transferred onto paper. Printing techniques evolved rapidly, and new procedures appeared to meet new needs or respond to new technical possibilities. It is necessary to highlight theetching , lithography , photogravure (which appeared from photography ), offset , or rotogravure . ¹ The modern techniques of xerography and inkjet are closely related to the computer processing of the data to be printed, which is sent directly to the printing machine and which has generated the appearance of specific computer- assisted publishing software .

Printing systems What is a print server

Printing systems are very varied, as well as their results. We can distinguish large groups with very different needs, processes and results: the artistic and artisanal ones ( small print runs), the digital ones (for domestic and small-scale commercial uses) and the industrial ones (for large quantities: newspapers, magazines, books, posters , containers, labels and other objects in general of mass production).

According to the matrix image What is a print server

• Embossed printing : The image to be printed is engraved in relief to the matrix, this relief will be inked and in contact with the paper to produce the copy. Examples: woodcut , letterpress , flexography
• Vacuum printing : The image to be printed is recorded on the matrix by emptying the parts that will receive the ink, and will produce the copy. An example is the black way . Examples intaglio ( etching , aquatint , …), rotogravure
• Flat printing : The matrix is ​​not engraved, the parts that will be inked will be determined by different techniques
  • By the repulsion between water and fat- bone : lithography and conventional offset .
  • By stencil : serigraphy .
  • Other techniques: inkjet printer , laser printer , thermal printer , collotype or collotype, driography .

According to matrix material

A wide variety of materials are used such as wood ( xylography ), metals ( intaglio ), stone ( lithography ), silk , plastic or nylon mesh screens ( serigraphy ) , linoleum ( linography ) , cardboard , acetate , polyvinyl , … etc.

According to the matrix engraving

• Direct printing : The engraving of the matrix is ​​done through the action of tools such as the burin or blades, which remove part of the material from the surface. Examples are the techniques of the burin, the dry point, the minced or the carborundum ( silicon carbide powder ). examples are woodcut and drypoint . What is a print server
• Indirect printing : The engraving of the matrix, a metallic plate ( zinc , copper , etc.), is done by means of the corrosive action of an acid (normally nitric ) on the surface, the parts that have to remain intact are protected with varnishes, sugar, resins, etc. Some examples of this technique are etching and aquatint .

Artistic

Artistic methods are those in which an image is manually engraved on a rigid surface, which will then house ink and be transferred by pressure to another surface such as paper or cloth, thus allowing multiple copies to be made mechanically.

• Xylography : the artist works on a wooden board, on which he carves the image by hand with a chisel or gouge, which will then be inked to be printed. 2
• Linoleum print – instead of wood a linoleum plate is used as the matrix. What is a print server
• Burin engraving : the big difference with woodcut is that the engraving is done on a metal plate and the ink is deposited in the grooves of the drawing to be transferred to the paper by capillarity.
• Dry point engraving : a fine and sharp punch is used to engrave, achieving shallower lines than with the burin.
• Etching : the plate, usually copper or zinc , is covered with a protective varnish and then the artist draws with a stylus, removing the varnish and exposing the metal. By immersing the plate in a corrosive solution, this will act to corrode the plate in the exposed parts.
• Soft varnish : this technique consists of using a varnish that maintains a sticky texture when it dries and that is covered with a very thin paper, of the so-called “silk”, on which it is drawn with a graphite pencil, with which adheres the varnish to the paper and when removing it reveals the metal of the matrix.
• Mezzotint : consists of achieving a dark and uniform tone in the entire plate, which is nuanced until white is achieved, by means of a surface burnishing process.
• Lithography : this printing technique, invented in 1796 by Aloys Senefelder , uses a previously polished limestone on which the image to be printed is drawn with a greasy material, either by pencil or brush. This process is based on the incompatibility of fat and water. Once the stone is moistened, the printing ink is only retained in the previously drawn areas.
• Screen printing : screen printing is a method of reproducing documents and images on almost all materials, which consists of transferring ink through gauze (previously it was with silk, stretched on a frame, hence the name). What is a print server
• Intaglio : Intaglio is a printing technique that uses metal dies engraved in such a way that the part to be printed is emptied into the copy. The word originally only designated engravings made by firing, and by extension it came to be used for engravings on all metals. Intaglio is an antagonistic technique to typography where the ink deposited on the surface is transferred, and not to the voids, of the reliefs. In intaglio techniques, the depth of the grooves that receive the ink determines the amount of ink that can be deposited and, consequently, determines the tonal intensity of the print. This technique includes the dry point , the black way , the burin and the stippling .as direct printing methods and etching , aquatint , soft varnish and photogravure as indirect methods. Most of these techniques today are only used to produce and reproduce works of art.

Digital What is a print server

Digital printing is understood as all that in which it is printed directly on paper (whether by injection, laser or other procedure) from a computer file, as opposed to other systems (typography, offset …), which use, for For example, sheet metal. It is currently the most common system in small print runs.

• Inkjet : common in domestic and small-run printing, due to its low cost.
• Laser Printer – Common for office documents, laser printing allows for more speed than inkjet.

Industrial

• Typography or typographic printing : it is the system of traditional movable type printing invented by Johannes Gutenberg . It was the usual system for printing books and other texts from the 15th century until well into the 20th century, when offset printing took over.
• Lithography : very popular in the 19th century to create and reproduce images (posters, etc.), it originally used a polished stone on which the image to be printed is drawn with a greasy substance. Later, with the appearance of rotary presses, metal or plastic rollers began to be used. A later evolution of this technique is offset printing. What is a print server
• Offset : similar to the lithographic process, using metal plates (usually in the form of a roller) and adding an intermediate plate to the process that improves the result. It is the most used system today for large print runs (books, newspapers, etc.).
• Screen printing – uses a mesh stretched on a frame, and is used to print onto a variety of materials, from T-shirts to tiles.
• Pad printing : uses a metal or plastic plate, coated with a photosensitive emulsion. Pad printing is known for its ability to print complex three-dimensional surfaces. It is widely used for marking industrial parts and advertising.
• Flexography – uses an embossed plate for printing, accepts a variety of ink types, and is used primarily for corrugated packaging, plastic and paper bags, self-adhesive labels, food wrappers, and also some newspapers.
• Rotogravure : the printing form is a cylinder engraved in low relief . It is mainly used for magazines and packaging.
• Collotype : Collotype is a process based on bichromated gelatin and is still used for very high quality printing. Like lithography, it is based on the incompatibility of water and oil, but allows variable ink densities to be printed.

History What is a print server

Woodblock printing in China

It was first documented in China in the Tang Dynasty , albeit as a method of printing patterns on clothing; the oldest surviving examples in China date from before AD 220, ³ and from Egypt in the 6th or 7th centuries . 4

In the Tang Dynasty, a Chinese writer named Fenzhi first mentioned in his book “Yuan xian san ji” that woodblock printing was used to print Buddhist scriptures during the Zhenguan years (627-649 AD). The oldest recorded Chinese print is a woodblock print of Buddhist scriptures from the Wu Zetian period (684-705), discovered in Tubofan (Xinjiang province ) in 1906. It was stolen by Japanese invaders, and is now preserved. is in the possession of the Museum of Calligraphy in Tokyo ( Japan ). The oldest documented printed book still in existence, a copy of the Diamond Sutra ( Buddhist text), is dated to 848, but a recent excavation at a Korean pagoda may have unearthed an even older Buddhist text dated to between 750-751. ^{56 In modern Chinese historiography, printing is considered one of the four} great inventions of ancient China. What is a print server

A memorial to the throne of 1023, China’s northern Song dynasty , documented that the central government at that time used bronze sheets to print paper money and also bronze blocks to print numbers and characters on currency today we can find these shades on Song paper money. Later in the Jin dynasty , people used the same but more developed technique to print paper money and formal official documents, the typical example of this type of bronze block letterpress printing is a Jin dynasty printed “cheque” of the year 1216.

Middle East

Woodblock printing on fabrics appeared in Egypt in the fourth century , it is not certain whether the technique was learned from the Chinese or developed independently. Block printing of Arabic text developed in Arab Egypt during the 9th and 10th centuries , it is unclear whether the blocks were made of wood or another type of material. ⁷ It appears that the technique fell out of use when movable type was introduced from China. 8

Printing in the West What is a print server

The block printing technique came to Europe from the Muslims, in 1300 it was a common method of printing on fabrics, the technique was used above all to print religious motifs. When paper became relatively easy to find around 1400 , stamps with religious images and playing cards began to be produced on a large scale . 4

Around the mid- 15th century , woodblock book printing, with text and images usually engraved on the same block, became a cheaper alternative to manuscripts and movable-type books . This type of printing was applied to short, lavishly illustrated works with great tastes, the best sellers of the time and with many different versions: the most common were the Ars Moriendi and the Biblia pauperum . There is still some controversy among scholars as to whether its introduction preceded or followed the introduction of movable type (the most widely held view), between 1440 and 1460.

Movable type printing press What is a print server

Movable type is a printing and typography system that uses moving parts with the different characters. This technique made the reproduction of a text or image easier and more flexible than manual copying or block printing.

Around 1040 , Bi Sheng (畢昇) created the first known system in China that used movable type made of clay that was very brittle. ¹⁰ Around 1298, Wang Zhen used more durable types made of wood. But at that time the most used method was still that of wooden blocks. What is a print server

Around 1450 Johannes Gutenberg introduced his movable type printing system, which is considered an independent invention in Europe. Gutenberg was the first to create the type pieces with an alloy of lead , tin , and antimony , which are the same components still in use today. 

Johannes Gutenberg began working in the printing press around 1436 when he became associated with Andreas Dritzehen, a man who had previously been trained in diamond polishing, and Andreas Heilmann, a paper mill owner . ¹³ It was not until 1439 that there is an official record of a legal claim against Gutenberg; Details of the printing press with an inventory of metals (including lead) and mold types appear in the document.

Compared to printing on wood, the mobile printing system allows the page to be adjusted more quickly and lasted longer. The metal parts of the printing press last longer and the letters were more uniform, which will lead to typography and typographic font types. The high quality and relatively low price of Gutenberg’s Bible (1455) demonstrated the superiority of mobile printing presses, devices that spread rapidly throughout Europe and later throughout the world ^, 1415and contributed to the development of the Renaissance. Today, virtually all types of mobile printing presses in existence ultimately derive from Gutenberg’s mobile printing presses, which is often regarded as the most important invention of the second millennium.

Post-Gutenberg evolution What is a print server

From Gutenberg to the 19th century , technological innovations in printing techniques are minor changes, aimed at improving efficiency and effectiveness. The alloy used to make the types remained the same. At the end of the 18th century , Charles Stanhope ( 1753 – 1816 ) built the first all-metal printing press that allowed the force required to print to be reduced by 90% and doubled the printable surface, ¹⁷ and with a production of up to 480 pages, it also doubled the production of previous. ¹⁸ Later lithography appeared , a printing system developed byAloys Senefelder , who, knowing that water and oil naturally repel each other, used limestone and a grease stick to make an impression, thereby revolutionizing graphic arts, allowing high-quality images to be printed. The current offset printing system derives from lithography.

An offset in operation

A modern copier

The rotary press , built in 1847 by Richard March Hoe ( 1812 – 1886 ), is a machinein which the images and graphics to be printed are curved on a cylinder, the first was already capable of 12,000 impressions per hour. The rotary printing drum was later significantly improved by William Bullock. Printing can be done on a large number of substrates, including paper, cardboard and plastic, which can be fed as cut sheet or continuous roll. The press prints and can also modify the substrate by die-cutting, overprinting or embossing varnishing. The need for large newspapers to have systems to meet the growing demands in record time led to a rapid development of the machines, with improvements occurring year after year. What is a print server

Printing was revolutionized during the 1880s with the invention of the linotype by Ottmar Mergenthaler ( 1854-1899 ) . This machine greatly improved the time required for text composition by replacing manual manipulation of movable type with keyboard entry of each line of text. The introduction of the text through the keyboard was translated into the mechanical composition of a matrix that served as a mold where an alloy outside of lead and tin was introduced, forming a single piece per line entered. This block was the one used to make the impression itself. The companyMonotype Corporation Ltd created its own typefaces over the years inspired by historical typefaces and most are still protected by copyright . This machine replaced traditional printing presses and in the field of book printing and the written press it reigned unchallenged from 1900 to the 1970s .

In the 1940s a substitute for line-blocks was devised, it was a plate that could be used to bring a text or an image indifferently. The ink was fixed on the desired positions thanks to an electrostatic charge (that is why the plate is called an electrographic plate), later the corona discharge was replaced by a laser. This technique, called xerography , was used by the Xerox company to create the first photocopiers , is the basis of today’s laser printers, and also paved the way for the design of photographic-type offset plates. What is a print server

In the late 1960s and early 1970s phototypesetting methods appeared . A system of mirrors with the characters cut out served as a template so that light could strike a sensitive surface that was developed and fixed like common photographic paper. The texts composed in this way were uprights on supports, the layout of the page was done manually. One stroke the page mount was finished the assembly was stenciled to create the plate that would be used for printing. Photocomposition and offset would last almost twenty years, the processes evolved with the appearance of lasers, which went on to print directly onto film, eliminating mirror systems. Since then, the printing was no longer done by pressing the characters on the paper , but rather the ink was absorbed by the paper where it had been fixed to the offset plate.

The great change during the 20th century began with the appearance of the personal computer and especially the Apple Macintosh at the beginning of the 1980s , which meant the democratization of computer-assisted publishing , previously reserved for mainframes and desktops. minicomputers (currently known as servers ). This microcomputer made it possible to do all the tasks involved in printing from a single workstation: acquisition of digital images , image editing, creation of vector graphics, composition of pages with specific software, which also allowed text and images to be combined. These operations were already possible on large dedicated systems, but at prohibitive cost. The Macintosh, in particular, helped make printing available to everyone.

Parallel to the evolution of composition, all the tasks involved in the graphic arts began to undergo profound changes. Thus, various devices were added to the workstation of composition, photographic treatment and page design, such as recorders or CTF ( Computer to Film ) that allowed printing directly from the computer to a film, and that could create the cliché of each color (four in the case of four colors) to produce the optical transfer plates. This enhancement eliminated the need for manual page layout and assembly. Even so, the optical transfer caused a loss of definition and did not prevent certain stains caused by the presence of dirt due to dust adhering to the plates.

The next evolution was the CTP ( Computer to Plate ) or plate engraver where the film is no longer passed through, but the printing plate is generated directly (generally aluminum and sometimes polyester ). One stroke created the plate, the operator only has to put it directly into the press. What is a print server

The latest evolution of the conventional offset is the embedding of the CTP to the press. This is what is called Direct Imaging . There is no longer any intermediate operation between the place where the pages are created and the press, the engraving is done directly on the plate-carrying cylinder of the offset press. The advantage is saving time and lowering production costs.

From photocopiers a new sector of activity has appeared, it is digital printing where all conventional systems have been replaced by image transfer systems based on photocopier technology, allowing immediate print runs faithful to the original document. The cost is much higher than that of traditional systems and this means that, for the time being, these systems are used for the production of short runs, such as in the case of self-publishing, doctoral theses or book printing on demand . In connection to databasesdigital printing systems allow the production of documents that contain text and images that vary over time, in the case of statistical yearbooks, timetables and rates, catalogues, etc. What is a print server

New printing techniques

3D printers What is a print server

The world of printing has experienced remarkable advances with the possibility offered by the new three-dimensional printers in fields such as health, art, architecture and industry. In health, they are used to make artificial organs, intelligent prostheses and 3D ultrasounds of future babies.

By sound waves

An innovative method of printing is one that uses sound waves to generate liquid droplets. The technique has been discovered by scientists at Harvard University and will be used, among other applications, for the manufacture of biopharmaceutical products. Liquid droplets, however, are used in uses as diverse as creating microcapsules for drug delivery, or printing ink on paper.

The client-server architecture is a model of software design in which the tasks are divided between the providers of resources or services, called servers , and the demanders, called clients . A client makes requests to another program, the server , who responds to it. This idea can also be applied to programs running on a single computer, although it is more advantageous in a multi- user operating system distributed over a network of computers . print

Some examples of applications that use the client-server model are Email , a Print Server, and the World Wide Web .

In this architecture, the processing capacity is distributed between the clients and the servers, although the organizational advantages due to the centralization of information management and the separation of responsibilities are more important, which facilitates and clarifies the design of the system. .

The separation between client and server is a logical separation, where the server does not necessarily run on a single machine nor is it necessarily a single program. Specific types of servers include web servers, file servers, mail servers, etc. While their purposes vary from one service to another, the basic architecture will remain the same.

A very common arrangement is multilayer systems in which the server is broken down into different programs that can be executed by different computers , thus increasing the degree of distribution of the system. What is a print server

The client-server network is a communications network in which the clients are connected to a server, in which the various resources and applications available are centralized; and that makes them available to the clients each time they are requested. This means that all the procedures that are carried out are concentrated on the server, so that the requests coming from the clients that have priority, the files that are for public use and those that are for restricted use, the files that are read-only and those that, on the contrary, can be modified, etc. This type of network can be used together in case it is being used in a mixed network.

Features print server

In the C/S architecture the sender of a request is known as the client . Their characteristics are:

• It is the one who initiates requests or requests, therefore it has an active role in the communication ( master or master device ).
• Wait and receive responses from the server.
• You can usually connect to multiple servers at the same time.
• It typically interacts directly with end users using a graphical user interface .

The receiver of the request sent by the client is known as the server . Their characteristics are: print 

• When it starts, it waits for client requests to arrive, then plays a passive role in the communication ( slave device ).
• Upon receipt of a request, it processes the request and then sends the response to the client.
• It generally accepts connections from a large number of clients (in certain cases the maximum number of requests may be limited).

In the C/S architecture the general characteristics are:

• The Client and the Server may act as a single entity and may also act as separate entities, performing independent activities or tasks.
• The Client and Server functions may be on separate platforms, or on the same platform.
• Each platform can be independently scalable. The changes made to the platforms of the Clients or Servers, whether due to updating or technological replacement, are carried out in a transparent manner for the end user. print server
• The interface between hardware and software is based on a powerful infrastructure, so that access to network resources does not show the complexity of different types of data formats and protocols.
• Its typical representation is a work center (PC), where the user has their own office applications and their own databases, without direct dependence on the organization’s central information system.

Servers can be stateless or stateful. A stateless server does not save any information between requests. A stateful server can remember information between requests. The scope of this information can be global or session-specific. An HTTP server for static HTML pages is an example of a stateless server, while Apache Tomcat is an example of a stateful server . print 

The interaction between the client and the server is often described using sequence diagrams. Sequence diagrams are standardized in the UML . It is important that clients do not interact with each other or that lower layer clients interact with higher layer clients, so everything has to go through the server.

Another type of network architecture is known as a peer-to-peer architecture because each node or instance of the program is a “ client ” and a “ server ” and each has equivalent responsibilities. Both architectures are in wide use. What is a print server

Comparison of the C/S architecture with other network architectures

Comparison with peer networks

Peer -to-peer networks , also known as peer-to-peer or peer-to-peer networks (abbreviated P2P ) are another type of network architecture. What is a print server

Comparison with Client-Queue-Client architecture

While the classic C/S architecture requires one of the communication endpoints to act as a server , which can be somewhat more difficult to implement, the Client-Queue-Client architecture enables all nodes to act as simple clients, while that the server acts as a queue that captures client requests (a process that must pass its requests to another does so through a queue, for example, a query to a database, so the second process connects to the database, builds the request, passes it to the database, etc.). This architecture makes it possible to greatly simplify software implementation. The P2P architecture was originally based on the “Client-Queue-Client” concept.

Multi-tier architectures print  

The generic client/server architecture has two types of nodes in the network: clients and servers . Consequently, these generic architectures are sometimes referred to as “two-tier” or ” two -tier” architectures .

Some networks have three types of nodes:

• Customers interacting with end users.
• Application servers that process data for clients.
• Database servers that store the data for the application servers.

This configuration is called a three-tier architecture.

• Advantages of n-tier architectures: What is a print server

The fundamental advantage of an n- tier architecture compared to a two-tier architecture (or a three-tier architecture with a two-tier architecture) is that it separates out the process, this happens to improve the balance of the load on the different servers; it is more scalable.

• Disadvantages of n-tier architectures:

• It puts more load on the network, due to a higher amount of network traffic.
• It is much more difficult to program and test the software than in two-tier architecture because more devices have to communicate to complete a user’s transaction.

Advantages print server

• Centralized control: access, resources and data integrity are controlled by the server so that a defective or unauthorized client program cannot damage the system. This centralization also makes it easier to update data or other resources (better than in P2P networks ).
• Scalability – The capacity of clients and servers can be increased separately. Any element can be increased (or improved) at any time, or new nodes can be added to the network (clients and/or servers).
• Easy Maintenance: With roles and responsibilities spread across several separate computers, a server can be replaced, repaired, upgraded, or even moved, while your customers are unaffected (or minimally) affected. This independence of changes is also known as encapsulation .
• There are sufficiently developed technologies designed for the C/S paradigm that ensure transaction security , interface friendliness , and ease of use. print 
• In the C/S networks, the other clients do not have access to the IP’s, which makes it difficult to track and/or hack users.

Disadvantages

• Traffic congestion has always been a problem in the C/S paradigm. When a large number of clients send simultaneous requests to the same server, the server must manage them and therefore can be saturated (the greater the number of clients, the more problems for the server). On the contrary, in P2P networks, as each node in the network also acts as a server, the more nodes there are, the better the bandwidth you have.
• The classic C/S paradigm does not have the robustness of a P2P network. When a server is down , requests from clients cannot be fulfilled. In most P2P networks, resources are generally distributed across multiple network nodes. Although some leave or abandon the download; others may still finish downloading by getting data from the rest of the nodes in the network.
• The software and hardware of a server are generally very decisive. Regular personal computer hardware may not be able to serve a certain number of clients. Specific software and hardware, especially on the server side, are usually needed to get the job done. Of course, this will increase the cost.
• The client does not have the resources that may exist on the server. For example, if it is a web application , we will not be able to write to the client’s hard drive or print directly to the printers without first removing the browser’s print preview window.
• In C/S networks, the only way to obtain the information is through the one provided by the server, with which the clients will not be able to share information with each other.

Address print server

Address methods in client server environments can be described as follows:

• Machine process address: The address is broken down as process@machine. Therefore 56@453 would indicate process 56 on computer 453. print server
• Name Server: Name servers have an index of all names and addresses of servers in the relevant domain.
• Packet Trace: Broadcast messages are sent to all computers in the distributed system to determine the address of the destination computer.
• Merchant: A merchant is a system that indexes all the services available in a distributed system. A computer that requires a particular service will check with the trading service for the address of a computer that provides that service.

Examples

Most Internet services are of the client-server type. The action of visiting a website requires a client-server architecture, since the web server serves the web pages to the browser (to the client). The user’s computer and web browser would be considered a client; and the computers, databases , and applications that make up PcSpell.Com would be considered the server . When the user’s web browser requests a particular PcSpell.Com article , the PcSpell.Com server collects all the information to display in the PcSpell.Com database., parses it into a web page , and sends it back to the client’s web browser .

Another example could be the operation of an online game . If there are two game servers, when a user downloads it and installs it on his computer, he becomes a client. If three people play on a single computer, there would be two servers, one client and three users. If each user installs the game on his own computer, there would be two servers, three clients and three users. print

Client-server cooperation print server

Multiple Server

For a process to be carried out in the best way, it is preferable to use different terminals performing the same task, rather than centralizing resources and using more hardware / software to carry out the same task. By running multiple servers, processing is faster, response time is decentralized, and reliability is increased.

Parallel process cooperation

The same process runs simultaneously ( redundant systems ).

Database cooperation print 

If certain existing information is required, why create it again, simply interact and take advantage of the information already created.

Basic components of the Client-Server model

In this approach, and with the aim of defining and delimiting the reference model of a Client/Server architecture, five components are identified that allow articulating said architecture, considering that every application of an information system is characterized by the following:

• Presentation/Collection of information.
• Processes.
• Information storage.
• Job positions
• Communications. print