Here's a simple way to make DIY durable molds using inexpensive ingredients. In this instructable i used my adjusted sticky playdough recipe.
I am making a large boquet of cold porcelain roses and was thinking of ways to make them faster.
There was the option of using silicone molds or plaster paris. However, I was a bit unsure how safe silicone was to handle and plaster paris usually ends up pretty messy.
So I settled on sticky playdough. This sticky recipe picked up all the finer details from the leaves I was casting. And the resulting leaf impressions were surprisingly clear.
Step 1: Sticky Playdough Recipe
However with this sticky playdough recipe, what makes it great for casting is that it is so soft and will enventually dry rock hard.
Instead of a ratio of 1:1 flour and water mix, I add half a cup of extra water.
2 cups plain flour
2.5 cups water
1 tbl tartaric acid / bicarbonate soda (adds bounce)
2 tsp teatree oil / orange oil / nutmeg oil (kills bacteria and prevents mould)
1 tbl salt
1/2 cup lime (calcium carbonate hydrated)
I lowered the amount of salt in the recipe as it has a tendency to create holes when drying, but there is a smooth finish when I added lime powder for some reason. You could chuck in some crushed Calcium tablets if you don't have any lime powder at hand.