D-grade plywood: The cheapest type of plywood veneers, these sheets typically haven’t been repaired. The flaws can be slightly larger and the knots in this type of plywood can be up to 2.5 inches in diameter.

CDX is a type of plywood. C in CDX means one side of the plywood is of grade C, and the other is of grade D.  Not that it matters a lot in the tasks they are meant for, but usually, the part of better grade is used on the more visible side while the one of lower grade is used on the less hidden side.  X stands for exposure, which is the type of glue used to bind the plywood together. However, note that the grading is not about the quality but the appearance of the wood because CDX is pretty strong and resistant to damage.  Besides, the tasks for which CDX is meant for requires more quality than good appearance.

CDX: CDX-grade plywood is typically inexpensive material, as it is made of the two lowest grades (C and D).

Judge which kind of plywood you need according to your actual situation. All kinds of plywood are produced by changsong wood with high quality. You are welcome to order.