I’m also not an expert with modelling choclate, but find it easier to use on larger modelling and sculpting pieces than smaller things. The one thing I do find with modelling choclate is it responds to heat, and if you have hot hands it softens quickly, so you need to work reasonably quickly. But what I do if it gets too soft is leave it to set a bit and work on something else and go back to it, as the beautify of it is you can still work with it I find. I like it as I find it more forgiving than gum paste etc which, once dry, that’s it and you can do no more. The modelling choclate does go hard once finished. I make my own and it sets quite hard. For more flexibility I also add a bit of fondant and/or marzipan … As I say, I’m not an expert and still experimenting so look forwards to reading what others have to say
You must never limit your challenges, instead you must challenge your limits
