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Before printing occurs, the frame and screen must undergo the pre-press process, in which an emulsion is 'scooped' across the mesh and the 'exposure unit' burns away the unnecessary emulsion leaving behind a clean area in the mesh with the identical shape as the desired image. The surface (commonly referred to as a pallet) that the substrate will be printed against is coated with a wide 'pallet tape'. This serves to protect the 'pallet' from any unwanted ink leaking through the substrate and potentially staining the 'pallet' or transferring unwanted ink onto the next substrate. Next, the screen and frame are lined with a tape. The type of tape used in for this purpose often depends upon the ink that is to be printed onto the substrate. These aggressive tapes are generally used for UV and water-based inks due to the inks' lower viscosities. The last process in the 'pre-press' is blocking out any unwanted 'pin-holes' in the emulsion. If these holes are left in the emulsion, the ink will continue through and leave unwanted marks. To block out these holes, materials such as tapes, specialty emulsions and 'block-out pens' may be used effectively.

The screen is placed atop a substrate. Ink is placed on top of the screen, and a floodbar is used to push the ink through the holes in the mesh. The operator begins with the fill bar at the rear of the screen and behind a reservoir of ink. The operator lifts the screen to prevent contact with the substrate and then using a slight amount of downward force pulls the fill bar to the front of the screen. This effectively fills the mesh openings with ink and moves the ink reservoir to the front of the screen. The operator then uses a squeegee (rubber blade) to move the mesh down to the substrate and pushes the squeegee to the rear of the screen. The ink that is in the mesh opening is pumped or squeezed by capillary action to the substrate in a controlled and prescribed amount, i.e. the wet ink deposit is proportional to the thickness of the mesh and or stencil. As the squeegee moves toward the rear of the screen the tension of the mesh pulls the mesh up away from the substrate (called snap-off) leaving the ink upon the substrate surface.

There are three common types of screen printing presses. The 'flat-bed', 'cylinder', and the most widely used type, the 'rotary',

Textile items printed with multicolored designs often use a wet on wet technique, or colors dried while on the press, while graphic items are allowed to dry between colors that are then printed with another screen and often in a different color after the product is re-aligned on the press.

Most screens are ready for re-coating at this stage, but sometimes screens will have to undergo a further step in the reclaiming process called dehazing. This additional step removes haze or "ghost images" left behind in the screen once the emulsion has been removed. Ghost images tend to faintly outline the open areas of previous stencils, hence the name. They are the result of ink residue trapped in the mesh, often in the knuckles of the mesh (the points where threads cross).

While the public thinks of garments in conjunction with screen printing, the technique is used on tens of thousands of items, including decals, clock and watch faces, balloons, and many other products. The technique has even been adapted for more advanced uses, such as laying down conductors and resistors in multi-layer circuits using thin ceramic layers as the substrate.

Stenciling techniques

A method of stenciling that has increased in popularity over the past years is the photo emulsion technique:

The original image is created on a transparent overlay, and the image may be drawn or painted directly on the overlay,photocopied, or printed with a computer printer, but making so that the areas to be inked are not transparent. A black-and-white positive may also be used (projected on to the screen). However, unlike traditional plate-making, these screens are normally exposed by using film positives.
A screen must then be selected. There are several different mesh counts that can be used depending on the detail of the design being printed. Once a screen is selected, the screen must be coated with emulsion and put to dry in a dark room. Once dry, it is then possible to burn/expose the print.
The overlay is placed over the screen, and then exposed with a light source containing ultraviolet light in the 350-420 nano meter spectrum.
The screen is washed off thoroughly. The areas of emulsion that were not exposed to light dissolve and wash away, leaving a negative stencil of the image on the mesh.

Another advantage of screen printing is that large quantities can be produced rapidly with new automatic presses, up to 1800 shirts in 1 hour. The current speed loading record is 1805 shirts printed in one hour, documented on 18 February 2005. Maddie Sikorski of the New Buffalo Shirt Factory in Clarence, New York (USA) set this record at the Image Wear Expo in Orlando, Florida, USA, using a 12-colour M&R Formula Press and an M&R Passport Automatic Textile Unloader. The world speed record represents a speed that is over four times the typical average speed for manual loading of shirts for automated screen printing.

Screen printing materials

Caviar beads: A caviar bead is a glue that is printed in the shape of the design, to which small plastic beads are then applied – works well with solid block areas creating an interesting tactile surface.
Cracking ink: Cracking ink effect is when the ink produces an intentional cracked surface after drying.
Discharge inks: Discharge ink is used to print lighter colors onto dark background fabrics, they work by removing the dye of the garment – this means they leave a much softer texture. The cons with this process is that they are less graphic in nature than plastisol inks, and exact colors are difficult to control. One of the pros of using this process is they are especially good for distressed prints and under-basing on dark garments that are to be printed with additional layers of plastisol. It adds variety to the design or gives it that natural soft feel.
Expanding ink (puff): Expanding ink, of puff, is an additive to plastisol inks which raises the print off the garment, creating a 3D feel and look to the design. Mostly used when printing on apparel.
Flocking: Flocking consists of a glue printed onto the fabric and then flock material is applied for a velvet touch.
Foil: Foil is much like flock, but instead of a velvet touch and look it has a reflective/mirror look to it. Although foil is finished with a heat press process it needs the screen printing process in order to ad the adhesive glue onto the material for the desired logo or design.
Four color process or the CMYK color model: Four color process is when the artwork is created and then separated into four colors (CMYK) which combine to create the full spectrum of colors needed for photographic prints. This means a large number of colors can be simulated using only 4 screens, reducing costs, time, and set-up. The inks are required to blend and are more translucent, meaning a compromise with vibrancy of color.
Glitter/Shimmer: Glitter or Shimmer ink is when metallic flakes become an additive in the ink base to create this sparkle effect. Usually available in gold or silver but can be mixed to make most colours.
Gloss: Gloss ink is when a clear base laid over previously printed inks to create a shiny finish.
Metallic: Metallic ink is similar to glitter, but smaller particles suspended in the ink. A glue is printed onto the fabric, then nano-scale fibers applied on it. This is often purchased already made.
Mirrored silver: Mirrored silver is a highly reflective, solvent based ink.
Nylobond: Nylobond is a special ink additive for printing onto technical or waterproof fabrics.
Plastisol: Plastisol is the most common ink used in commercial garment decoration. Good color opacity onto dark garments and clear graphic detail with, as the name suggests, a more plasticized texture. This print can be made softer with special additives or heavier by adding extra layers of ink. Plastisol inks require heat (approx. 150°C (300°F) for many inks) to cure the print.
PVC and Phthalate Free: PVC and Phthalate Free is relatively new breed of ink and printing with the benefits of plastisol but without the two main toxic components. It also has a soft texture.
Suede Ink: Suede ink is a milky colored additive that is added to plastisol. With suede additive you can make any color of plastisol have a suede feel. It is actually a puff blowing agent that does not bubble as much as regular puff ink. The directions vary from manufacturer to manufacturer, but generally up to 50% suede can be added to normal plastisol.
Water-Based inks: these penetrate the fabric more than the plastisol inks and create a much softer feel. Ideal for printing darker inks onto lighter colored garments. Also useful for larger area prints where texture is important. Some inks require heat or an added catalyst to make the print permanent.

Versatility

Screen printing is more versatile than traditional printing techniques. The surface does not have to be printed under pressure, unlike etching or lithography, and it does not have to be planar. Different inks can be used to work with a variety of materials, such as textiles, ceramics, wood, paper, glass, metal, and plastic. As a result, screen printing is used in many different industries, including:

Semiconducting material

In screen printing on wafer-based solar photovoltaic (PV) cells, the mesh and buses of silver are printed on the front; furthermore, the buses of silver are printed on the back. Subsequently, aluminum paste is dispensed over the whole surface of the back for passivation and surface reflection. One of the parameters that can vary and can be controlled in screen printing is the thickness of the print. This makes it useful for some of the techniques of printing solar cells, electronics etc.

One of the most critical processes to maintain high yield. Solar wafers are becoming thinner and larger, so careful printing is required to maintain a lower breakage rate. On the other hand, high throughput at the printing stage improves the throughput of the whole cell production line.

Screen printing press

To print multiple copies of the screen design on garments in an efficient manner, amateur and professional printers usually use a screen printing press. Many companies offer simple to sophisticated printing presses. Most of these presses are manual. A few that are industrial-grade-automatic printers require minimal manual labor and increase production significantly.

Rotary screen printing

A development of screen printing with flat screens from 1963 was to wrap the screen around to form a tube, with the ink supply and squeegee inside the tube. The resulting roller rotates at the same speed as the web in a roll-to-roll machine. The benefits are high output rates and long rolls of product. This is the only way to make high-build fully patterned printing/coating as a continuous process, and has been widely used for manufacturing textured wallpapers. A large number of such machines have been supplied by Stork B.V..

A screen is made of a piece of mesh stretched over a frame. A stencil is formed by blocking off parts of the screen in the negative image of the design to be printed; that is, the open spaces are where the ink will appear on the substrate.

Stenciling techniques

Screen printing materials

Versatility

Semiconducting material

Screen printing press

Rotary screen printing