Other things you need to know about commercial plywood

Timber grade

Commercial plywood grading systems use the letters A, B, C and D, etc. However, in most woods you will see two letters. One letter indicates the level in front of the board, and the other letter indicates the level on the back, or the part you can't see when installing. Usually, the level of one side will be lower than the other side, which is the side you want to use later.

The exterior panels usually have a high grade. You will want to make sure that you choose the highest level, any that may be exposed to the weather or need excellent strength. A level of C-D is usually available for internal structure, but if it is not adequately covered, you should not consider using it. Sometimes you may see an additional score with an X at the end, such as A-CX. This means that the board has reached the standard for external use. For projects that require high-end completion, choose a higher level. These should have little to no knots and voids and should provide a good, smooth surface stain or paint.

size

Commercial plywood comes in several different thicknesses, widths and lengths to suit your project needs. Some sheets are so thin that they are flexible enough to bend the structure to form a uniform shape, while others are incredibly thick and made of things like weight and wind. Paper can be very long, but you can usually ask for a hardware store or lumber yard to cut the paper to the size you need.