Playdough

Happy New Year folks!

I'have a few questions about playdough. My little lad has gone a bit mad for it recently. In fact, he got so many toys for Xmas we could open a toy shop, but he loves playdough more than any of them. The trouble is, conventional playdough really dries my hands. I'm not sure what it is, the flour? The salt? Cream of tartar? Kneading bread dough or any kind of cake dough doesn't normally irritate my skin that much (well, maybe a little bit). I'm really not sure what it is about playdough my skin hates. The conventional recipe I have is, 2 cups flour (doesn't say plain or strong), 1 cup salt, 2 cups water, 2 tablespoons oil, 2 teaspoons cream of tartar and colouring.

Also, I want to make one that's quite sticky, a bit like plasticine, so that you could make models by sticking pieces together which conventional playdough doesn't do very well. So, the other day I did an experiment. Here's what I did (I only made a small batch):

half cup strong flour, half cup cornflour, tablespoon salt, teaspoon vinegar (had no cream of tartar), colouring, tablespoon cinnamon, cup cold water. Mixed till smooth, then heated on hob till it came together.

The reason I used cinnamon, apart from that it smells nice, was because ground cinnamon turns into gelly when heated with a bit of liquid. So my thinking was, it might help with the stickiness.

Freshly made, this dough was perfect. It was soft, sticky enough to make models with but not too sticky so it goes all over your hands and the table. Oh, and it didn't dry my hands at all. However the next day it became really sticky, so I kneaded in a few more tablespoons of strong flour (about a quarter cup?). That was a bit too much, it became dry and crackly, so I added a tablespoon water. Been using it for three days now and it's not bad, although still a little too sticky. I have to keep it in the fridge between uses so it molds well but doesn't stick to everything. Unfortunately cooling makes it quite tough for my little one to roll and press stamps into.

I suppose you can't have something that sticks really well to itself, but doesn't stick to your hands. At the end of the day plasticine sticks to hands too. Or is it possible after all?

So, I'm still looking for ways to improve my playdough. Could someone tell me why you need cream of tartar in it? As a preservative? Or does it do something to gluten? If so then what?

Why so much salt? Is it to stop kids eating playdough, or does it have any proper function?

Has anyone else ttried replacing some of the flour with cornflour, potato starch or other starch, and what ratios worked best for you?

Any ideas greatly appreciated.