Screenprinting gives your designs fantastically rich colour and a quality of image that just isn’t possible with most other techniques – which partly explains why it’s become so hugely popular for designer prints in the past few years.
However, creating a screenprinted design isn’t as simple as drawing something and then hitting Print. With screen-printing, your colour palette is limited by the number of inks you can use, which means you need a few tricks up your sleeve if you’re going to create the best images possible.
Design studio Waste started making screen-prints with a home-made set-up in their garage, where they produced simple one-colour posters. They quickly found themselves bitten by the screen-printing bug. Now they have a professional print studio in a basement of an old hardware shop in Nottingham.
In this tutorial you’ll learn how to colour up a four-colour design for screen-printing using Photoshop and Illustrator. There are insider tips on how to give your image more depth using highlights and shadows, how to create halftone fills that create two tones from one colour, and how to create colour separations.
Even if you’re not going to screen-print your designs, this shows you how to convincingly fake the look.
Adobe Photoshop Time to complete
If you’re creating your own piece of art for this tutorial, scan it in at 300dpi in greyscale. Next adjust the sketch to make the lines black and get rid of any grey areas. Choose
Image > Adjust > Brightness and Contrast, tick the ‘Use Legacy’ box and tweak the brightness and contrast until the lines are as black as possible.
Create a new artboard (
File > New) and in the new window name the document ‘zombie print’ and resize it to 297x420mm, setting the resolution to 300dpi, and the colour mode to CMYK. Create a new layer ( Cmd/Ctrl + Shift + N). Name the layer ‘outline’ and set the blending mode to Multiply.
Next copy the adjusted sketch and paste it (
Cmd/Ctrl + C > Cmd/Ctrl + V) into our new document, and resize to fit leaving a little space around the illustration.
Create a new layer and name it ‘Colour 01’. Start to colour up the illustration using the Brush tool (
B). Pick a single colour and begin colouring the relevant areas. The colour will sit behind the linework because we’ve set the outline layer to Multiply – this helps us see where and what the design looks like while we colour it up. This design will have four colours. We need to make sure that each new colour is created on a new layer and named for our reference: this will make it easier to split out into colour separations later.
We need to ensure that we slightly overlap adjacent areas of colours to avoid gaps caused by registration errors in the printing process. This is called ‘trapping’.
The best way to add trapping to your colours is by adding a stroke to each colour fill. Do this by hitting
Cmd/Ctrl + click on the first colour layer. This selects your first colour. Then choose Edit > Stroke and enter the width of the stroke you want to add, set the colour to match and the location to Outside.
Check whether you need to add more or less stroke by changing the opacity of the outline layer so you can see the colours through the outline. Try and get your colours to sit half in the outline.
Once the design is coloured we can give it depth by adding highlights and shadows. This we do in Illustrator so we can get sharp lines. Save your design so far and open up Illustrator. Choose
File > Open and choose your saved design, click open and in the import options choose ‘Flatten Photoshop layers to a single layer’ as we’re only using it as a guide in Illustrator. Lock the design ( Cmd/Ctrl + 2) and hide the artboard.
Now using the Pen tool (
P), add white highlights to the design. It’s worth taking your time here to follow the shape of the design; play with additional shapes such as circles. Once you’re happy with your highlights, select them all using the Selection tool ( V) and copy and paste them into the Photoshop file. Rename the new layer ‘highlights’ and rearrange the layer order so that the layer is directly below the outline layer.
Repeat step 7 to add the shadows but this time using a fill of 20% black. Once you’re happy, select and copy your shadows. Go back into your Photoshop file and create a new layer. Name it ‘shadows’ and change the blending mode to Multiply. Paste your shadows in as pixels and arrange the layer so it’s directly below the outline layer.
The design should have a lot more depth now. Earlier we said it was a four-colour job, but now we’ve added the light grey shadows it’s looking like a five-colour: this is our secret weapon. Now we need to turn the shadow fill into bitmap dots that we will later merge with the black outline layer to create one colour with two tones. Select and copy your shadows again. Choose
File > New and create a document in the same size but in greyscale. Paste the shadows onto the artboard.
Image > Mode > Bitmap, set the output to 300dpi and set the method to Halftone Screen. Now in the halftone screen set the frequency to 45 lines per inch, the angle to 90º and the shape to Round.
You’ll now see that the solid grey fill as been changed into black dots that when printed will give the illusion of a grey tone. If you’re happy with the number of dots Select All and copy it (
Cmd/Ctrl + A > Cmd/Ctrl + C).
Click back on the main design window and create a new layer directly below the outline layer called bitmap and change the blending mode to Multiply. Paste your new bitmap shadow.
Now hide your original shadow layer by clicking its eye symbol in the Layers palette (don’t delete it, in case you decide to create a different bitmap fill). Now merge both the outline and bitmap layers together by selecting both the layers and choosing
Layers > Merge Down ( Cmd/Ctrl + E) and change the layer’s blending mode back to Multiply.
We are including our own registration marks, which will help align the art properly when it comes to printing so the colours ‘register’ or match perfectly. This is a simple grid made up of four squares. The grid is drawn in a three-pixel line on the outline layer, and the blocks that fill the holes in the grid are drawn on the colour layers.
Now it’s time to create colour separations. To create colour separations ready to print we change the colour of each ‘colour’ layer to black, at 100% opacity. Choose
Image > Mode > Greyscale and tick Don’t Flatten. Now use the Levels feature ( Image > Adjustments > Levels or Cmd/Ctrl + L), select the black colour droplet, and click on each colour fill except the highlight layer to change them to absolute black.
The file is now ready for output. Print out your separations on film for best results. Most laser printers are able to print on acetate or OHP transparencies that are acceptable for screen films. Turn off all layers except the one you wish to print and the highlight layer, then print. Now, turn that layer off and turn on the next layer for printing. Once they’re all printed, tape them to a window one by one, making sure they all line up correctly, and making sure they’re 100% opaque black. Now, you’re ready to make screens.