I have never used this myself. Having decorated cakes for a quite a few years, your question really interested me. I am way behind on new products.

According to what I see on the internet, Non-Toxic Paste (NT Paste) is very popular for flower making when decorating cakes. The paste supposedly offers more versatility as there is less breakage when handling and assembling, and dusting colours can be washed off and other colours can be reapplied.

How to make Non-Toxic (NT) Paste

1 cup flour
1/2 cup water

Combine the flour and water and mix until creamy. More or less water may be added to obtain the desired consistency.
The mixture may be brought to a boil (stir!) to make a more durable and thicker paste (or maybe a tasteless gravy).

Tips:
Don't dump this in the sink or toilet without mixing in a LOT of water first... otherwise a clog may result!
Dried areas will clean more easily if soaked with water first.

I saw a number of web sites that refer to NT Paste as “cold porcelain paste.” However, I see recipes for cold porcelain paste are different from the one posted above. And, I saw a number of sites that said to NOT apply cold corcelain paste directly to cakes.

Possibly your instructor can describe the differences and you can enlighten all of us. That would be great!