One of the great mysteries in this industry (or let’s rather say, everybody seems to have his or her own way - as with so many procedures in this job, but I have come across a lot of people who are unsure how to get a good finish) is the colouration of silicone. Technically, silicone wants to stick to itself, but then again - it does not really. I like using Plat Gel and Tin Gel, but especially when applying Tin Gel in thixotropic layers, it tends to come apart if you left the prior layer to fully cure before aplying the next one.
The ‘non-sticking’ of materials to silicone is a serious problem, but when keeping in mind a few tricks, your results should be good.
tintig silicone is a lot easier than painting onto it. Quite a few things will work and if it cures, it will not rub off. Silicone pigments are the best to use, I like the ‘Smooth On’ ones for their deep saturation and consistency. Also, the base tones red, blue, yellow and black and white are very ‘clean’, meaning it is easily possible to mix any tone and shade. In addition, I also have the brown and flesh tone on the shelf.
Apart from silicone pigments, you can use oil paints - it works, but I do not really like to use them, the pigments tend to be big and normally the oil paint is too thick and you will have to water them down with some kind of solvent, like white spirit and that will affect the curing of your silicone, especially when you add a lot of paint to your mix. I also like to add some red flock to flesh tones, since it distorts the very even colouration and thus makes it a bit more lifelike.
Basically, try adding whatever you feel like, but try first. Many things may works, others won’t.
there are many ways of painting silicone and every manufacturer seems to have a solution for it. Some people like to use the silicone they used for the cast as a paintbase, but especially with condensation cure silicone that does more harm than good, because it might not cure.
Looking at what a paint is, you have got three basic ingredients: pigment, solvent and a bonding agent.
For pigmenting I simply use silicone pigments
As my bonding agent I use a one part “bathroom sealant” type silicone, Dow Corning 734
It dries quickly and is already nice and runny and it also bonds well to both condensation and addition cure silicone
As a solvent I use something rather special - it is called cyclopentasiloxane and a base to many makeup and bath-products and is one of the few harmless substances in this industry. It does not affect the curing of the silicone, does not smell and evaporates. This stuff can be bought from jacobsons chemicals as “Diluent No.5″ or from Kryolan if you ask them kindly.
