As you can see on my design practise blog I have been thinking about working with a scratch off effect that I have seen been done in college before. I knew it involved washing up liquid but I tried to do a bit of research into this before trying for myself.
Many of the tutorials I found were quite vague when it came to amounts of ink compared to washing up liquid simply saying to add a 'bit', however I did find one tutorial that said to add 1 part washing up liquid to 1 part acrylic, so if I screen print using this technique I will try to ensure the liquid and acrylic are 50/50 and then add a bit of binder to ensure it pulls through the screen.
I found a few online tutorials and many of the suggested using sticky backed plastic, I also spoke to some of my peers that also worked with this effect and they recommended the sticky backed plastic idea too.
Then rather than paint the individual cards, it's much quicker to paint a large sheet of sticky backed plastic with your mixture, (I used a roller to get a smoother finish). I painted about four layers, but this will depend on the colour & thickness of your paint. As long as it covers the writing underneath one or two layers of paint might be sufficient.
The tutorials suggested simply painting onto the plastic but I wanted to screen print this as after seeing some peers do this the effect is much smoother and so more realistic.
Once you have painted (or printed) the plastic you can then cut it as you wish and it is then ready to stick onto your design.
You can see below that these have been stuck onto cards.
This then scratches off easily.
I have also seen this applied with a paint brush but again this isn't as neat as screen printing would be.
If I used this technique to screen print I could expose a screen with the shape I wanted to print the effect with and then simply use the washing up liquid mixture as a normal ink. I could apply the sticky back plastic to the design and line this up in the printing bed or print directly onto the plastic and then stick this onto the design.
Such interactive print really excites me and I would love to try this method for myself.