If you are not a total purist do not forget cork and foam ....... very effective carp biscuit " FLYS " can be achieved with a wine cork or piece of trimmed foam. Attached to the hook with a pellet band and stop through the imitation with a boilie needle. They stand up to casting very well.
Just drop the biscuit you are planning to use into a glass of water and craft chosen material to look as similar as possible.
Best of all ...... no wonga, no wait and no bald deer
We'll make a tyer of you yet !