What you talking ’bout Willis?

Quite a few of you may be new to printmaking and some of the terminology. This page is a little dictionary of terms for screen printing that I may have written on posts across the blog. If you can’t find a word you are looking for just ask! I love talking about prints and sharing the knowledge wealth. You can find my contact info on the About page 🙂

Abrade – To wear off or down by scraping or rubbing, to scrape off. To cause the surface of an object to not be smooth.

Amberlith or Rubylith – Rubylith® and Amberlith® brand masking films are light safe knife cut films coated onto a clear polyester backing sheet. These films can be cut manually or on a plotter to produce masks for film contacting and plate making and film positives.

Artwork – Also may be referred to as “screen art”. Screen art refers to artwork that is already set up for the screen printing process. Artwork in general may or may not be ready to go to screen. It is important to note that you will need your artwork set up correctly to obtain good results in screen printing. More on this to come.

Belt Oven – The piece of equipment used to cure the shirts. It contains several infrared heat panels that heat the ink to about 330 degrees Fahrenheit.

Bleeding – This occurs when an ink that is printed migrates outside of its printed area into surrounding areas of the shirt. This can occur with 2 different colors printing closely as well. This is much like when you use a sharp tipped permanent marker on a heavy paper, sometimes when you draw a line the ink “bleeds” into the surrounding paper fibers causing spider or vein like edges.

Block Out – This is an emulsion like chemical that is most often not light sensitive. It is used to fill any unwanted openings in your stencil on the screen after exposure and washout.

Butt, Butt Registration – When the edges of 2 different printed colors come edge to edge but do not overlap.

Capillary Films – Pre-sensitized emulsion on a film base. It comes in sheets and rolls. This would be used instead of a direct liquid photo emulsion.

Catalyst – A substance, usually used in small amounts relative to the reactants, that modifies and increases the rate of a reaction without being consumed in the process.

Choke – Choking is a type of trap that reduces the size of the first color printed slightly and covers it with another color to trap the underlying color with the overlapping edge of the top color.

Color Composite – A full color rendition of your design exactly the way you want it to be on the shirt.

Continuous Tones – These are the tonal ranges we are familiar with in photographs. The tones are rendered in a continuous shading in full color.

Coverage – The quality or amount of ink that is laid down onto a shirt when printed through the screen. Also referred to as the opacity.

Crest – A design printed over the heart area of a tee shirt.

Cristalina – A small flake of reflective foil or plastic suspended in plastisol used in glitter inks for specialty printing.

Cured Emulsion – Emulsion that has been exposed to light. Curing is the actual chemical process by which the emulsion becomes insoluble in water.

Cured Ink – Ink that has been through the oven at about 330 degrees Fahrenheit. Curing is the actual chemical process by which the ink dries and bonds to the shirt fabric.

Degrease – To remove grease, oil, or the like, from, esp. by treating with a chemical. To remove all soil, grease or other foreign matter.

Dot Gain – A condition where printed dots enlarge from the desired or original size. This is most often due to the excess accumulation of ink around the outside of the stencil perimeters. It can cause areas of halftones to get very dark and thus incorrectly reproduces the art.

Drying Cabinet – This is the place where you dry your freshly emulsion coated screens. It can be self contained and light safe with vents or fans that circulate the air for quick drying of emulsion on screens.

Dual Durometer – This is a squeegee that is made up of two different durometer squeegees sandwiched together. It provides benefits from both of the two durometer characteristics.

Durometer – One of several measures of the hardness of a material. Hardness may be defined as a material’s resistance to permanent indentation. The durometer scale was defined by Albert F. Shore, who developed a measurement device called a durometer in the 1920s. The term durometer is often used to refer to the measurement, as well as the instrument itself. Durometer is typically used as a measure of hardness in polymers, elastomers and rubbers.

Dye Migration – This is a problem that begins in the shirt manufactures production facility. Sometimes a vendor will make too many shirts of a particular color, say yellow. Then they get an order for those shirts but in navy. If they do not have the shirts in stock in navy, the quickest way to supply them is to re-dye the yellow shirts they already have in stock. This causes the fabric to become swelled with dye. When you go to print a light colored ink on these shirts, it is very likely that the navy dye will sublimate into the ink layer and cloud it with a navy tint thus ruining the true color of the ink printed. This happens a lot with navy, maroon, and other darker colors. This can also occur with 50/50 poly/cotton blends. Reds, maroons, royals, navies and black are especially susceptible to this problem.

Dyed Mesh – Mesh fabric tinted, often yellow or amber, to help reduce light transmission and scatter.

E.O.M. – “Emulsion over Mesh.” This is the measured percentage of emulsion past the threads in relation to the total thickness of mesh and emulsion. It is basically your stencil thickness.

Emulsion – A light sensitive liquid chemical that is applied to the screen, it becomes most light sensitive when dry.

Emulsion Remover – This part of the process is done when we need to reuse the screen for another job. The chemical needed is called “reclaimer” or stencil remover. It most likely will need to be diluted but there are some that you buy ready to use. It is most often put in a chemical resistant spray bottle and kept with other chemicals in your washout booth.

Exposure Latitude – This is the range of exposure time that will produce a usable stencil during screen exposure.

Extenders – Chemical additives in plastisol ink used to smooth the texture, increase volume, reduce opacity, while not reducing viscosity.

Fibrillation – This occurs when you wash a printed garment and the underlying fibers of the shirt come through the print. They appear fuzzy and tend to make the print look faded.

Film or Film Positive – This is the clear piece of “plastic” with your artwork printed onto it in all black. Translucent papers such as vellum are also used.

Flash Additives – Most often a catalyst added to ink to reduce the flash cure time needed.

Flash Cure – The process of exposing a printed shirt to a heat source less than that of the curing oven in order to make the ink dry to the touch.

Flocking – A type of raised decoration applied to the surface of a fabric in which an adhesive is screen printed on the fabric in a specific pattern, and then finely chopped fibers are applied by means of dusting, air-brushing, or electrostatic charges. The fibers adhere only to the areas where the adhesive has been applied, and the excess fibers are removed by mechanical means.

Flood and Stroke – These terms refer to the act of spreading ink over the screen and then pushing the ink through the screen respectively.

Four Color Process – In this type of industrial or commercial printing, the technique used to print full-color images, such as color photographs, is referred to as four-color-process printing, because four inks are used: three primary colors plus black. The “subtractive” primary ink colors are cyan (a bright blue), magenta (a vivid red-purple), and yellow; which are abbreviated as CMYK.

Frame – The rectangular wood or metal body used to hold the stretched mesh in a fixed position.

Halation – This is light scatter caused by light passing through the clear film base on its way to the emulsion. This can be minimized by making sure your film positive comes in contact with the emulsion on the same side that the image was applied to the clear film base.

Halftone – Halftone is the reprographic process that simulates continuous tone imagery through the use of dots, varying either in size or in spacing. ‘Halftone’ can also be used to refer to the image that is produced by this process. Where continuous tone imagery contains an infinite range of colors or grays, the halftone process reduces visual reproductions to a binary image that is printed with only one color of ink. This binary reproduction relies on a basic optical principle; that these tiny halftone dots are blended into smooth tones in the brain through the human eye.

Halftone or Grayscale – This is artwork made to reproduce continuous tones by printing small dots in varying proximity and or density. This is like the photos you see in newsprint, made up of dots.

Indirect films – This is a light sensitive, hand or mechanically cut light blocking material on a clear film base that is exposed, developed and/or cut, weeded before application to the mesh as a stencil.

Ink Degrader – An ink solvent that breaks down the ink before reclaiming.

Ink Well – The side of the screen where the ink is placed.

Knit – This is what we call the style of sewing that is used to make shirts and other garment. There are different types of knit with varying degrees of smoothness and textures.

Knocked Out – Omitted portions of artwork in a design that prevent other colors from over printing.

Light Table or Exposure Unit – This is the piece of equipment that will shine light on your emulsion coated screen curing the emulsion, (or not curing the emulsion where your artwork is). This is known as “exposing” or “burning” your screen.

Mesh Count – This is the number that refers to the size of the openings in between the filaments of thread in the mesh. Lower numbers, like 110, have bigger openings and smaller numbers, like 355, have very small openings. With plastisol inks lower mesh counts leave a heavier, rubbery deposit of ink on the shirt. Using a higher mesh count will produce a much softer fell to the print.

Mesh or Fabric – The polyester material stretched over the frame through which the ink passes.

Mesh Prep or Degreaser – A chemical or solvent wash designed to degrease and thoroughly clean the screen. This can be a professional screen printing product or a common household detergent.

Micro Grit – A fine yet coarse powder that acts as an abrasive to the mesh. It helps make small , uniform abrasions on the screen.

Mono-filament – A fiber, strand or thread made of a solid flexible, most often polyester material.

MSDS – Also known as, Material Safety Data Sheets. These are informational documents with chemical specifications that are often required by law to be kept on hand with the chemicals during use and/or transit.

Multi-filament – A strand or thread made up of twisted or woven smaller threads.

Newtons – The newton is the unit of force derived in the SI system; it is equal to the amount of force required to accelerate a mass of one kilogram at a rate of one meter per second per second. Kilonewtons are often used for stating safety holding values of fasteners, anchors and more in the building industry.[2] The safe working loads in both tension and shear measurements can be stated in kN (kilonewtons).

Outline – A line surrounding an inner “fill” of another color.

Pick Up – The ink that is deposited on the bottom of a screen when printed after a color that has already been printed and is still wet.

Pigment – A Dry coloring matter, usually an insoluble powder, to be mixed with water, oil, or another base to produce paint and similar products.

Pinhole – Small unintended holes in your stencil usually due to dust or other debris contaminating the emulsion during coating or drying.

Plastisol Ink – Plastisol ink is a type of ink used for silkscreen printing on to textiles. Plastisol inks are the most commonly used inks for printing designs on to garments, and are particularly useful for printing opaque graphics onto dark fabrics. Plastisol inks are not water-soluble. Because the ink is made up of PVC particles suspended in a plasticizing emulsion, the ink will not dry if left for extended periods of time. Plastisol inks are recommended for printing on colored fabric and on lighter fabric; plastisol is extremely opaque and can retain a bright image for many years. Plastisol inks will not dry, and need to be cured as a result. Curing the inks can be done with a flash dryer, or a belt oven. Most plastisol inks need to reach a temperature of about 350 degrees Fahrenheit before being fully cured. Plastisol tends to sit on top of the threads instead of soaking into them, giving the print a raised, plasticized texture. When printed through higher mesh counts, plastisol inks can produce a softer feel.

Pre Shrinking – The process of flash curing the shirts on the pallets before printing in order to shrink the garment. This prevents registration problems due to garment shrinkage.

Press Wash – This is an ink solvent that is emulsion friendly and can be used on the press during printing for color changes. It will not damage the stencil.

Printable Area -The area of the screen where the film can be placed without distortion to the artwork. This will tend to be center balanced.

“Printer” or Platen – The screen or artwork used to print a particular color.

Printing Wet – The process of only flash curing an under base, if present, then printing subsequent colors without flash curing them.

Reclaiming – This part of the process is done when we need to reuse the screen for another job. The chemical needed is called “reclaimer” or stencil remover. It most likely will need to be diluted but there are some that you buy ready to use. It is most often put in a chemical resistant spray bottle and kept with other chemicals in your washout booth.

Reducers – Ink additives used to lower the viscosity of inks.

Registration – The alignment of one color of artwork with another. Multi color prints require the different colors of the artwork to line up correctly in relation to one another.

Resolution – The sharpness or clarity of your print.

Re-tension-able Frames – Frames that have the ability to stretch the mesh during mesh application and later on in the life of the screen. Roller frames are a common type of this frame. This has certain benefits over static frames.

RIP – Raster Image Processing. This is a term often referring to software designed to maximize the output onto your digitally produced film positive.

Roller Frames – Re-tension-able frames that use opposing roller bars to tighten the mesh. The roller bar itself constitutes the frame.

Scoop Emulsion Coater – A trough like tool used to coat the screen with emulsion.

Scorching – This often happens with 100% cotton white shirts but may also happen to other light colors as well. It is a yellowing of the shirt fabric caused by slightly over heating the cotton fibers. When scorching is light, it can be removed with a chemical spray called scorch-out. Most often it is simply hydrogen peroxide solution which acts as a weak bleach not affecting the print generally.

Screen – This is the platen or “printer” for each color of the design.

Serigraphy – A print made by the silk-screen process usually by hand also known more commonly as a screen print

Simulated Process – A process in which multiple opaque colors are used to create a realistic photo like image. Using specific spot colors and halftones the process simulates continuous tone images and from a reasonable viewing distance can seem photorealistic.

“Soft-Hand” Extenders – This is an ink additive that will “thin” the ink and reduce opacity. It is often used to print certain inks through higher mesh counts on lighter colored shirts. This produces a very soft feel to the print on the shirt.

Solvents – A substance in which another substance is dissolved, forming a solution or a substance, usually a liquid, capable of dissolving another substance.

Spot And Dot – A combination of spot color printing and halftones.

Spot Color – A spot color is any color generated by an ink (pure or mixed) that is printed using a single run. Spot colors tend to have large open areas as well as lines in the stencil where the ink will pass. There are no dots or line screens.

Spot Gun or Spot Cleaning Gun – This is a hand held machine that forces a cured plastisol ink solvent through the shirt to remove unwanted ink marks from finished shirts such as those caused by finger prints or pinholes.

Spray Adhesive – Aerosol spray glue used to keep the shirt in a fixed position on the pallet.

Static Frame – This is a frame that is fixed and welded at the corners. There is no ability to make any adjustments to the frame or mesh. The mesh is stretched and applied to the screen usually by adhesive and the mesh will lose tension over time eventually needing to be replaced.

Stencil Break Down – This occurs when the emulsion did not adhere properly to the mesh or when the emulsion was not cured properly. The stencil will begin to fall apart and break away from the screen.

Stencil Thickness – The depth or thickness of your emulsion in the stencil. The distance from the emulsion to the screen within the stencil design itself.

Stirring Stick – A wooden or plastic stick used to stir the emulsion.

Substrate – This is any item that is being printed on. The side of the screen that comes in contact with the substrate in known as the substrate side.

Substrate Side – The side of the screen that comes in contact with the substrate in known as the substrate side.

Thixotropy or Thixotropic – The property exhibited by certain gels of becoming fluid when stirred or shaken and returning to the semisolid state upon standing.

Trap – Color art separations where the edges of the different colors overlap one another slightly.

Under Base – Printing colors on dark garments often requires a layer of white ink printed under and before all other colors. This allows the colors to stay true and maintain opacity over the dark fabric.

Vacuum – The vacuum on the light table ensures that the film is in direct contact with the emulsion coated screen and no light is able to pass around the film.

Vacuum Blanket – The rubber cover that covers the screen in the exposure unit. It is pulled around the screen by a vacuum.

Vector Art – The representation of continuous lines and shapes in digital art through mathematical algorithms.

Vellum – This was originally a translucent material made from animal skin. Today it is a translucent paper product used in laser printers to produce film positives. It is prone to shrinkage by the fuser and can be problematic with multi-color jobs. They most often need a RIP program to achieve any usable density.

Washout – The step in which you “wash out” the uncured soluble emulsion from the screen with water.

Washout Booth – The piece of equipment used to wash screens in. It will always have a light panel in the rear so you may see through the screens as you work with them. Several steps in screen printing are actually done here.

Water Soluble – Able to be dissolved in water.

…is for ZZZZZZ. Thanks for the lecture, Hannah.

Bombyx Mori