Final answer:
Plaster grounds are the best form work for wet plaster as they establish the correct thickness and alignment of the plaster on walls.
Step-by-step explanation:
The best form work for wet plaster is plaster grounds. Plaster grounds are used to establish the correct thickness and alignment of the plaster wall. They act as a guide for applying the wet plaster, ensuring that the plaster thickness is consistent throughout the wall.
Unlike bead boards which are more common in exterior or semi-exposed conditions, or guides which might be temporary reference points or tools used in plastering, plaster grounds are specifically designed to fulfill this function in interior plastering applications. Lath is also important in plasterwork; it's the backing structure that supports the plaster, but in itself is not a form work.