Experimenting with different mould-making materials

Mosaic forms made from baked polymer clay - the pink
surround was added to contain the moulding material

I constructed two small areas of 'micro mosaic', one using angular pieces and the other circles. I then tried making a mould of each using different mould-making materials.

Moulds created with Siligum (blue) and Pinkysil (pink)

The blue moulds were made with Gedeo Siligum Moulding Paste - this is a two part (blue and white) putty that you mix in equal quantities; it only has a 5 minute working time and de-mould time of about 10 minutes.

The pink moulds were made Pinkysil Silicone - this came in bottles and you mix equal quantities; the working time is 6 minutes and de-mould time of 20-30 minutes (depending on thickness).

Samples made with Siligum moulds

Here are some samples made with the Siligum moulds, using black polymer clay and then Pearl-Ex powders on the raised surface. The middle one has a coating of Envirotex Lite epoxy resin but disappointingly this reduces rather than enhances the effect of the raised mosaic impression.

I also tried making a mould using scrap polymer clay but it did not press far enough into the joint spaces to make a useable mould. I have orderd some Sculpey Moldmaker to try - will post my results with this when I have tried it.

My Conclusions

Both materials make a flexible mould. The Siligum (blue) is firmer and better for imprinting polymer clay, which is the purpose I want to use it for. The Pinkysil (pink) is quite rubbery and very flexible - it would be better for a mould around a dimensional object that you would need to peel away. It was not firm enough to imprint the surface of rolled polymer clay.

Due to the short working time of both materials, I would suggest you only make one mould at a time - it was difficult to judge how much I needed to fill my mosaic forms without wasting too much. It was easier to pour the Pinkysil into the mosaic forms and get a smooth surface; the Siligum started to set before I could smooth the surface - but I did try making two moulds at the same time.