That's a technique used in Brazil for years, it is call "Biscuit" there. Maybe because I am so use to using I just love it. Is air dry and the best for me is that you don't have to bake it to get cured. I have been using for at lest 25 year for the majority of my projects. Today I will post the recipe and how to do it.
Cold Porcelain
Ingredients:
2 cups of white glue ( the one kids use for school project)
2 tbsp white vinegar
2 tbsp baby oil
2 cups of corn starch
2 tbsp of baby lotion (Must not be with silicon)
Put the 3 first ingredients in a glass container and mix very well.
Add the corn starch sift and mix again.
Will look like marshmallow liquid to put on ice cream.
Make sure the corn starch is completely dissolved and put in the Micro on high for 30 seconds, take out, mix and put back for another 30 seconds, keep doing for about 3 to 4 minutes. In some micros took me 10 minutes to be ready. You will see that the mix is getting hard, in my micro takes 4 minutes and 30 seconds. Make sure you memorize the time it takes, because next time you don't have to go through the same 30 second process. At this point you should have a little glue in the bottom and the mix is almost a big ball.
Put it on a clean surface, spreading a little bit of corn starch and work the dough, but be careful because it's very hot.
At this time add the baby lotion.
and work into the dough until you feel the dough malleable and smooth.
Should not stick in your hands
Put in a plastic bag, take any air out and let the dough to be worked on the next day.
I use the same day and the dough is not elastic and breaks when it dries. Take in consideration that this dough shrinks 10% when dried completely. It takes up to 5 days to dry completely depending on the size of your piece. After drying the piece will be pretty sturdy.
The best pigmentation for cold porcelain is oil paint to be mixed in the dough before sculpting or you have many ways of coloring the finish pieces. The finishing of a cold porcelain is very similar with porcelain that is why they call it cold porcelain. After drying, it can be sanded for a very smooth surface.
Cold porcelain and water are not friends, after drying if you wet the piece it will leave a mark, so you really need to seal your piece for durability. I personally prefer spray sealers but brush on acrylic varnish also works well. Just about any clear spray or varnish will work but acrylic or polyurethane based sealers are best.