Screen Print
DIY Screen Printing with Jan
Welcome to my DIY screen printing class. I will show you how to manufacture a screen using photo emulsion, but with kitchen equipment. This is a great if you wish to understand the basics of screen printing, if you want to experiment, make small print runs, or have limited space or a limited budget. Normally, it's done with big machines. Here, you learn how to do it at home!
 A screen, that is basically a stencil held together by mesh. Here you can learn how to produce that using photo emulsion. |
 These are all the tools we will need. On the far left, my screen. Then, some special things: screen mesh; a coating trough; a pot full of photo emulsion; a squeegie. Then, a couple of everyday tools: staple gun, masking tape, some rags and spoons. On the far right, there's my home made exposure unit: it consists of a simple sheet of window glass that I have placed over a strong flood light. Note the rubber snake to the right, on the window glass. |
 Well you can buy ready made screens, but you can save a lot of money building your own. Here, I have one of these cheap streched canvases from a poundshop. I just rip the canvas off, because all I want is the stretcher. It has an inner length of 30cm. |
 I stretch the mesh onto the bare stretcher. Again, you can buy special mesh for this purpose; it is made of nylon and very strong, and has a precise resolution, for example: 48 dots per centimeter. Well but here I use curtain mesh from a fabric shop: a bit more rough, but much cheaper and perfect for my training purpose. |
 Stretch the mesh evenly and staple it as tight as you can on the canvas. You can test by moving along the edge with your finger; you will need quite a lot of staples! |
 Now look at my coating trough and my squeegie. All these are approximately 30cm long, and that must correspond to the inner length of my stretcher. With this, we'll be able to print stuff in a size that is about A4, - a common format. |
 In my right, a professional squeegie with a strong blade. In my left, a cheap substitute, again from the poundshop: a bit more wobbely, but will do the job. |
 Here's another reason why we want all screens to be of the same size: later, when we have made lots of them, we can actually put them neatly on a shelf. Or under a table, yes. |
 This is a coating trough and that's a very handy tool that I found hard to substitute. It is some sort of a half pipe. These plastic bits get on the edges. A very handy thing - you will see for what purpose! |
 I place the empty screen in front of me and fill the trough with my photo emulsion. - Photo emulsion is something you need to get from your screen print supply (probably online). That stuff has an astonishing quality, once it is dry: where it gets exposed to light, it becomes fixed, but where it does not get exposed to light, it dissolves in water. This is what we will use. |
 Place the trough on the bottom of the screen, just on the frame. |
 Tilt the trough, until the emulsion touches the screen all the way along. |
 Then go up slowly: let the emulsion flow into the mesh. The idea is to cover all the holes in the mesh evenly. |
 Do the same procedure from the inside of the frame. Basically you can repeat this as long as you wish, until you achieve a nice even film all over the mesh. Put excess emulsion back into the pot and close the lid. |
 Now the screen needs to dry. Notice that the emulsion is already photo sensitive. Yes - but not very much (not as much as is photographic paper, for instance). So we're not wasting time, but dry it quickly with a hairdryer - and not in broad sunlight. |
 Here I test if the coating is all dry, simple trick: if the blurbs and blops at the edge are all dry, then the film in the middle will be dry as well. |
 This is an acetate film we have produced last time; we can use anything that casts a shadow to produce our image. Acetate are, in fact, the most common way to transform an image to screen print. Here, we'll be even more simple: instead of acetate, I'll use an object - a rubber snake. |
 Now I put my screen on the exposure unit, face down. Between the sceen and my window glass, I have placed the rubber snake. |
 I've put some weights on the top so that nothing moves, and used some bags to cover the screen so that no light touches it from the top. Then I have switched on the light - here, a 500W builder's flood light as available from any hardware shop. |
 This is the same viewed from below. You can see the light, the window glass, the rubber snake, the screen. Exposure time in this setup was about 20 minutes. But you may have to experiment to find the right exposure time as it varies from light bulb to light bulb, and also depends on how dark your image is (a rubber snake is 100% opaque so I could actually expose much longer; if I was to use acetate, that would depend on how black and opaque my acetate is... I usually produce two identical acetate and double them up to make them proper pitch black and be on the safe side). |
 When the exposure time is over, go and wash the screen under running water. Note that you won't need shrubbing nor soap, just (cold) water - but a lot of water. The stuff is like sugar really, it dissolves after a while. |
 So that's how it looks like washed out. Note that while you wash, the image will slowly begin to appear - but it has to appear totally clear. |
 Here I hold the screen to the kitchen lamp to check if I have truely washed out everything. |
 Then place the screen - face up - back on the exposure unit, switch light on, and dry it with a hair dryer. This gives you some extra control, and the extra exposure will harden the emulsion more. |
 Almost there! Now, I stick some tape over the gaps at the edge of the screen. |
 Taped up all the way and ready to print! Well yes, actually, it would be better to cover the entire frame with tape (like brown tape), to protect it from becoming wet. But here I can't wait. |
 So I place the ready made screen onto the sample t-shirt, and I put some ink next to the image on the screen surface. What ink? Well it's textile printing so I bought some textile ink. For everything you want to print there's different ink. For paper printing, you can use normal acrylic paint; but you should really mix it with "screen printing medium" which is basically retarder, so that the ink does not dry on the screen. |
 I take a little squeegie, and I push the ink all the way through the screen onto the t-shirt. |
 E voila, my rubber snake image on the t-shirt! |
 Don't forget to wash the screen immediately after you stopped printing; if ink dries on the screen, you can forget about it, that's just like letting colour dry in on a brush. |
 My print on the t-shirts only needs to dry... Well yes, I can speed that up using a hair dryer again. And most fabric inks require heat-curing, that means, the colour needs to be heated up to become wash fast; which you may do using an iron. Have fun! |
Thanks to Michael Bucknall for taking the photos.