Cold porcelain is not a porcelain at all. It is a kind of dough which can be prepared at home. Main ingredients are white glue (PVA glue) and corn flour. Sometimes I use potato flour. There are thousands recipes online so it is easy to find one you like. The dough you get is smooth, easy to work with. It is air dry "clay". You have to give min 24 hours to dry the item you create. When dried cold porcelain is very hard and it is possible to make even very thin pieces. The biggest problem for me is shrinkage. You have to be prepared that dried item will be approx. 30% smaller than the wet one. Also in thickness. So if you make something 3mm thick, you ventually will get the thing only 1mm thick. The other problem is keeping the shape of drying items. For example if you cut a circle you will never get flat circle if you leave it unpressed. If you press it it will not dry. Now I am trying to dry some items between to layers of plastic. It has been 24 hours now and they are still wet. Because of big shrinkage, you can't make a cold porcelain creation on the core of something. Some days ago I made a ring on metal band. It was perfect and suddenly after a week the big crack appeared.
The cold porcelain dough has nice ivory colour and I would be happy if it will look the same when dried. Unfortunately dried cold porcelain, specially this one based on corn flour looks like dry pasta, which is not really attractive. The solution would be to add some paint and knead it to cold porcelain. I used white acrylic paint but you can use any colour you want. Dried cold porcelain is not very good for sanding a surface, so it is better to smooth your creation in the wet stage. Thin edges can be sanded and thicker items can be drilled but you have to be careful not to put too much pressure as you can brake. To finish my jewellery pieces I paint them and varnish. Acrylic paint and varnish could be used. Today I've got Pebeo Porcelaine 150 paints. They can be bake in the oven if applied on proper fired porcelain but don't do it on cold porcelain. The next time I will try to bake slowly cold porcelain in the oven (put the item into the cold oven and warm it up to 170 degrees), than paint it and bake again. We will see if it will be any better...
Here is a link to the website with recipe and tutorial for cold porcelain. I recommend to read comments as well, some other recipes there
And here are some of my cold porcelain jewellery: