Woodpeckers Baltic Birch Plywood, 3 mm 1/8 x 12 x 20 Inch Craft Wood, Pack of 6 B/BB Grade Baltic Birch Sheets, Perfect for Laser, CNC Cutting and Wood Burning,

Mine were not flat. I'm trying to fix the warping with weights but it's not quite working yet.

4 out of the 6 boards I ordered were too warped for laser cutting. Emailed Woodpeckers directly and they sent 4 board immediately. 5 stars for customer service. While they explained that some warping is inevitable due to storage conditions and humidity, I could not help comparing them to Glowforge proofgrade materials that have been perfectly flat for all the lots I have ever ordered from them. Cost wise, if I factor in the need to apply a layer of transfer tape on both sides before laser cutting, the savings from using proofgrade from Glowforge is hardly worth the effort. Eventually, I ended up gluing the boards in pairs to make 1/4" thick material, and in the process flattened them by clamping to a flat board while the glue dries.

These sheets are excellent for use on a 10W or higher laser. There are no voids in the ply layers and there is at least one clear side. Even the back side is usable since there are not a lot of large plugs or dog bones seen as patches. Excellent material at a reasonable price.

Inferior product. Excessive splintering and a lackluster finish that requires great care in sanding and does not accept stain well. Is probably best used to produce sawdust.

I was told this would be good plywood but I only had 1 sheet that was cuttable. I attempted a calibration cut on one area of a board and after 3 cuts that didn’t go through we changed the settings. It finally cut through so I decided to cut my design on the other end of the board. It would not cut through the board! Made no sense how it would cut on one end of the board and not the other. Switched to a new piece of wood and had the same problem. I won’t be buying again.