The thin layers of plywood can often splinter and chip when cut with a power saw, resulting in an ugly edge that looks like this:
To prevent your cut line from tearing:
1. Always use an appropriate blade for plywood, and be sure that it’s sharp. The blade that came with your saw – whether you bought or rented it – is likely inadequate.
2. Be sure the good face of your plywood is closer to the outside of the blade. So on a table saw, the right side should be facing up, and when using a handheld circular saw, it should be facing down.
3. Then, add a strip of masking tape to both the top and bottom of the sheet, directly over the cut line.
4. Lastly, always make sure the saw is running and at full speed before making your cut. Push with a steady, consistent speed all the way through.
5. Peel back the tape, and marvel at your finely cut edge.
Note: This masking tape trick also works when using a drill or router.