DIY Life

I have to admit that silk-screening, AKA screen printing, is a craft that was once a little bit mysterious to me. One reason it confused me for such a long time is that the tools and terms used in it are specialized: if you aren't a silk-screener already, or being directly taught by one, it might be difficult to figure out what "photo emulsion" is and how it works. (This is probably the case with most printmaking processes!)

However, screen printing is really not difficult at all. Join me after the break to learn about several methods. This article is the first in a series: next week, we'll learn all about the compact Japanese screen printing system called the Print Gocco, and we'll even use it to make a nifty holiday card.

Gallery: Made by screen-printing

Gallery: Screen Printing Process

If you are as confused as I once was, try to catch this episode of DIY Network's Craft Lab the next time it's on. The guest, Seth Savarick, silk-screens polymer clay to create boxes and switch-plate covers, so part of the show is devoted to setting up your own inexpensive screen-making operation in the easiest possible way.

There's an online tutorial, but it isn't as clear as watching the show. (See the videos listed later in this article for something similar.) That, and reading Annie Stromquist's book Simple Screenprinting: Basic Techniques and Creative Projects, helped me understand the process.

All you're really doing is creating a stencil: it's a piece of fabric, usually mounted to a frame, with areas that ink can flow through and areas that it can't. The areas that ink can flow through are your design.

This method of printing has been around for about a century. Initially, the designs on most screens were hand-cut from film. The film has been mostly replaced by chemicals that harden when they've been exposed to light. The design is the part of the screen that is kept covered. In spite the of the term "silk-screening," most screens in the post-WWII era are made of polyester, not silk.

If you see a screen-printed item in a museum or gallery, it will probably be called a serigraph; that's just a technical term.

Speedball makes several great screen printing kits that are widely available, and helpful for beginners. If you'd rather not buy a kit, the supplies you need are:

• Screen material: If you're just starting out, you'll probably want to get material specifically made for screen printing. Experienced printers sometimes use any sheer, non-stretch fabric that happens to be at hand. The specific screen you should use depends on what sort of artwork you're printing and what you plan to print on. 110 seems to be commonly recommended as a starting point.
• Frame: A basic square that you'll attach your screen to. These can be wood or metal. Metal is better if you plan to wash and reuse your screen a lot.
• Something you can use to attach the screen to the frame; the screen should be stretched tightly. What you use depends on what kind of frame you have and, maybe, what materials you have at hand.

or

• Pre-made screens (optional): A frame with the screen already attached to it. It makes your life easier, and also ensures that the screen material is stretched correctly. It's the previous three items on this list in one time-saving package.

and

• Photo emulsion: You use this light-sensitive chemical to prepare a screen. Diazo is the kind recommended in most of the tutorials I consulted for this article. You can also buy this in the form of a film, but make sure that the screen printing film you purchase is "photo-sensitive" (there's another type that must be hand-cut).
• Scoop coater (optional): A tool that helps you get an even layer of photo emulsion on your screen. (It looks a lot like the letter brackets that players use in the game Scrabble. See the videos linked below for a demonstration of its use.)
• Something to print on: Fabric or paper. Popular choices are t-shirts (which need to have a board put between their layers before printing), tote bags, muslin, printmaking paper, watercolor paper, and so on. It's possible, but beyond the scope of this article, to screen onto glass and ceramic items. Screening onto vinyl stickers is also possible and common (it's how most bumper stickers are made). You should have some scrap paper or fabric (newsprint, cheap muslin, thrifted t-shirts, etc) to test on before you print.
• Screen-printing ink: There isn't much point in making the screens if you don't have any ink to use with them. Different kinds of ink are used on paper and fabric. Look for fabric ink if you plan to print fabric, and be sure to follow the instructions on the ink you buy. (For fabric, you can even get glow-in-the-dark ink.)
• Tape: Use this to seal up the edges of the screen -- you can use duct tape, or more specialized tape that can be purchased where screen-printing supplies are sold.
• Rubber gloves: You don't want photo emulsion or screen-printing ink all over your hands.
• Palette knife: Some people use these to stir their ink and to lift excess ink from a screen when you've finished printing with it, so you can save the ink to use next time.
• Squeegee: You need this to spread the ink across the screen: it's your tool for actually making your print. The one you use should be wide enough to cover your entire design in one swipe. The spreading end should have a rectangular shape; you can't use the same squeegee you would use to wash your car. You'll use a different squeegee depending on whether you're working on fabric or paper.
• Design: The picture you want to print. This needs to be printed on a transparency in solid black ink. (You can even touch it up with a magic marker.) Anything under the black parts when you expose the screen to light will be part of the positive image in the stencil you create. If you want to print in more than one color, you have to create one screen for each color. The screen should feature only the elements of your design that are meant to be printed in that color (i.e., you must do color separation). You'll print in layers, one color at a time, lining the layers up carefully.
• Light source: This can be the sun (UV light works best), or it can be a very bright bulb (which will probably take much longer). You'll also need a dark place where you can keep the screen after it's been coated with photo emulsion, so you don't accidentally expose it before you're ready.
• Something to stabilize your screen for printing: Most people use hinge-clamps or a full screen-printing unit (a work surface made of screen-holding hinge clamps mounted to a board, for around $50). T-shirts are often printed on a special frame. You'll see a lot of variation in this category when you look at the articles linked from this one.
• Other optional supplies: Screen wash-up, screen cleaning brush, screen opener (helps remove ink that's blocking parts of a screen), Blockout (a material that repairs areas of screen that develop "pinholes" -- spaces where the photo emulsion has crumbled away), stencil remover (allows you to reuse -- "reclaim" -- a screen by removing all the photo emulsion), drying racks for both emulsion-painted screens and wet prints, thin pieces of wood to slightly raise the screen while printing (if you aren't using hinge clamps), screen de-greaser (especially useful on a reclaimed screen -- you can use something like Mr. Clean or Simple Green for this), etc.
• EZScreenprint sells special paper that is essentially a screen with photo emulsion, suitable for small prints. It isn't in a frame, so it may be tricky to print with. However, it can be used to screen print onto curved items like lampshades, and would be fine for small projects like cards.

Many online suppliers seem to be in the business of supporting large print shops. The home printer, or an artist working in a small studio, can probably get what they need at an art store; my favorite is Blick. Some craft stores also at least sell screen printing inks, if they don't sell a full line of supplies. (Speedball screen printing kits are widely sold even in stores that sell no other such supplies.)

A few more sources are linked throughout this article; Screen Printing Superstore and Silk Screening Supplies both look particularly promising.

Making a screen stencil

To create a stencil, let's assume you're starting with a pre-stretched screen that has been de-greased. (See the videos below if you need instructions for how to stretch a screen on a frame.) You'll load the scoop coater with photo emulsion, coat the screen, and allow it to dry flat in a dark place. You don't want the emulsion to harden until you're ready to put your design on the screen.

If you don't have a scoop coater, you can load the screen with photo emulsion in the same way that you will eventually ink your design: use the squeegee.

The screen has two sides: one that will be against the paper, and one that you will work on. Keep in mind that the side of the screen that has the lip of the frame all around it should be face up when you print.

To be absolutely safe, you should work on your screen in a darkroom-like situation before you want to expose it. In practice, a minute in a dimly-lit area (no UV light!) while you position your design and, potentially, cover your screen with dark fabric, probably won't hurt it. It depends which method you choose to expose your screen.

You can create your design however you wish, but it must be printed in black onto a transparency (also called a 1:1 film positive -- if you can't do this at home, you can have it done at almost any copy shop). Place the design face-up on the face-up side of the screen. You should be able to read any text normally.

(Some tutorials have you put the transparency on the face-down side of the screen in a position that is reversed if you try to read it from that side. The point is that if you look at the side of the screen you're printing on, rather than the one that touches the paper, you should be able to read or imagine yourself reading any letters in the image, without them being reversed.)

If you're taking it outside, you'll want to have the screen on a board, and you'll want to put a piece of Plexiglas or glass on top of the design. If you're using an indoor light, you should set your screen on a flat surface to expose it.

Once the screen has been exposed to bright light for a while (depending on the materials you use, it might be anywhere between one and fifteen minutes), the emulsion should have hardened.

You'll pull off your design, and immediately rinse through the areas of the screen where the design was, removing all the photo emulsion from those areas. A hose with some kind of nozzle is useful here, if possible. When all the emulsion has been removed from your design, you're done. Let your screen dry again.

You can now do a few things to support your screen and improve the quality of your prints.

Check the photo emulsion for holes that aren't meant to be part of your design: you can fill them in with more photo emulsion or with Blockout. You should also tape the edges of the screen, between the frame and the edge of the emulsion, with either one of the special tapes marketed to people who screen print, or with duct tape or masking tape; this keeps ink from leaking out at the ends. You'll get better results if you do both of these things.

Printing the screen

The difficult part is done. The screen should be secured to a surface with something like hinge clamps. The flat side of the screen should be face down, with the lip of the screen pointing up (it should be like looking into a tray). You should be able to see your design looking as you will when you print it.

The screen should not be flush against the table; rather, it should be raised about an eighth of an inch. You can use thin pieces of wood, like paint stirrers, to prop it up.

Before you print on anything expensive, you should probably do a test run on scrap paper or fabric.

After you position the item you want to print under the screen in the way you want, you drizzle a line of ink across the top edge of the screen, above the design. With your squeegee, but without pressing down, pull some of the ink towards you until it covers your design. This is called flooding the screen.

Move the squeegee back to the top of the screen, press down at an angle, and pull it towards you again. This time, your item should be inked. Lift the screen and take your item to dry. Don't stack drying items unless there's space between them, as on a drying rack.

When you're finished, clean the ink off of your screen. You may want to pour excess ink back into the jar, so it can be re-used.

That's really all there is to it. If you're making multiple items that you want to be identical, or especially if you need to use multiple screens on a single item, you'll need to create a registration system so that everything lines up. This could be two perpendicular lines crossing each other (+) at each corner of where you want your item to sit while it's printed, or it could be registration tabs.

Tutorials

The last two sections were a description of the process, not a tutorial. If you're going to make your own prints, you need more information. The following tutorials and resources are great (though they occasionally contradict each other):

• Shannon Gerard's How to Silkscreen Posters and Shirts at NoMediaKings will definitely get you up and running.
• Sanderpoo's What you need to know to screenprint thread on Craftster: lots of technical details. This thread should be read by anyone who has a serious interest in this topic.
• How to Screen Print a Poster, by Anthony Skirvin, is on a site with a name that some people might find offensive; it's too good not to include here. Anthony shows you how to create a multi-color art print, from the concept stage to getting it out in the mail. You'll see some specialized, higher-end equipment here, too.
• Stan Pope's Silk Screen Printing for Fun: no pics, alas, but because the author of this tutorial is not a professional artist or art student, everything is presented in clear, conversational language, without the assumption that you want to do more than make a few things for people you know.

Craftster has two topic categories for screen printing, under the general heading of Image Reproduction Techniques:

• Silk Screening: Discussion and Questions (where you can ask anything you need to ask).
• Silk Screening: Completed Projects (where you'll see things like a university project in which the student had to create designs illustrating a subculture -- she chose Mods; and a post about printing on curtains for a newly remodeled school).

Screening on t-shirts

It seems like the majority of online discussion about screen printing is done among people who just want to make some t-shirts. Printing on a t-shirt is just like printing on any other fabric, although some fabrics like canvas might be easier because they don't stretch (screen-printed tote bags are also very common).

To make them washable, inks used for screening on fabric need to be heat-set. Follow the instructions on the ink you actually use.

CRAFT has posted an archive article from their first issue, CRAFT-101: Silk-Screening. This brief illustrated tutorial will help you choose which images are appropriate for silk-screening onto a t-shirt, then show you how to create the screen and put the image onto the shirt. It's a great way to decorate your own shirts, particularly if you need a bunch of them for a team or event but don't need enough to make up the minimum order that a print shop requires.

Kingi Carpenter, the owner of Toronto's Peach Berserk, designs and sells silk-screened fabrics and garments made from them. She offers a screen printing workshop for locals, but if you can't make it to Toronto, you might be interested in the DVD version, currently sold in the US by Fred Flare: Silkscreen Workshop DVD.

Videos

There are a lot of videos on YouTube that address this topic. Some are better than others. As with the tutorials, these videos sometimes contradict themselves and this article, because there is more than one way to do some of these things.

• Learn how to screenprint your own t-shirts (6:23): Bre Pettis from MAKE and Matt Stinchcomb from Etsy show you the basics of printing on fabric. They want you to know that "there's only one good design: the wolf." Funny and informative. You can also download their supplementary screenprinting PDF with supply list. (Caveat: I think they spend a lot more time showing you how prepare the screen with photo emulsion than actually printing the shirt, and they're so stoked about giving the wolf LED eyes -- "Let's set this wolf's eyes on fire!" -- that they don't really mention that ink on fabric almost always needs to be heat-set. Also, they definitely have access to special equipment that you won't have at home... like the flash dryer they use to heat-set their shirts. Still, this is a great video.)
• Tutorials from Ryonet: This array of videos (64, at this writing) by Silk Screening Supplies could almost be seen as a course in screen printing. Some are too specialized and advanced for general interest, seemingly created to supplement or sell high-end equipment to pro t-shirt printers. Others are of interest to the average crafter or artist. Try the following, some of which are the first in their respective series (most are 9-10 minutes long): Screen Printing Overview, Artwork Basics Pt. 1, Screen Preparation Pt. 1, Screen Exposure Process Pt. 1, Screen Printing One Color Pt. 1, Screen Printing Multiple Colors Pt. 1, Cleanup Pt. 1, Advanced Techniques Pt. 1.
• Tutorials from EZScreenPrint.com: Part One, Part Two, Part Three. Videos in this series vary in length, but none is more than a few minutes long. The method demonstrated here is almost identical to the one that Seth Savarick used on the episode of Craft Lab that I mentioned earlier in this article, involving a "paper" that is actually a pre-coated screen. However, this method probably isn't as physically stable during the printing process as using a screen in a frame.
• Silk Screen Print Frame (3:23): An inexpensive way to build a frame. Part of a detailed series (see the "related videos" sidebar). This guy likes to use cheap filmy curtains from the dollar store and the thrift store as his screen material, and seems to get decent results.
• Silk Screen Printing (0:38): An assembly-line-type process.

Many more videos are available covering just about every facet of this process, though more seem to focus on t-shirt than on printing on paper. To find them, see the keywords silkscreening and screenprinting.

I'm not going to discuss methods here that use nontraditional materials (like creating a screen by drawing on it and then filling any area you don't want to print with ordinary glue), simply because the results are not predictable or as good. If this concept interests you, check out this Cheap Screen Printing Tutorial.

That's all I have for you today. Join me next week to learn about the Print Gocco: the compact Japanese screen-printing import that has recently taken the American craft world by storm. I'll tell you all about it, and then we'll use it to make holiday cards. See you then!