the process of making a proof of a printed work, engraving, etc.

proofing could be done on a low-cost printer

make (fabric) waterproof

if you are using a piece of lightweight canvas it will be necessary to proof the fabric when complete

make a proof of (a printed work, engraving, etc.)

proof each plate and print it on acetate first

activate (yeast) by the addition of liquid

proof the yeast with the teaspoon of sugar