Their Baltic Birch is marine grade (water resistant) and sanded butter smooth, it’s nice.
Alternatives to Proofgrade Wood
These are other sources for plywood in 12x19" or 12x24" size, with two good faces and a finish on both suides, and a core suitable for laser cutting with a Glowforge Performance Series laser, comparable to Medium/Thick Proofgrade plywoods:
Maple
- Finished Maple, 1/8 inch, 12x19 inches, Double Sided — Craft Closet
- 1/8" Prefinished LaserLumber™ Premium – GS2 Awards
- LaserBits Maple Laserable Wood Laminate | JPPlus
Walnut
- Finished Walnut, 1/8 inch, 12x19 inches, Double Sided — Craft Closet
- 1/8" Prefinished LaserLumber™ Premium – GS2 Awards
- LaserBits Walnut Laserable Wood Laminate | JPPlus
Cherry
- Finished Cherry, 1/8 inch, 12x19 inches, Double Sided — Craft Closet
- 1/8" Prefinished LaserLumber™ Premium – GS2 Awards
- LaserBits Cherry 12" x 24" Laserable Wood Laminate | JPPlus
Basswood
For the Aura/Spark owners:
12x12", 1/8" thick, MDF-free lightweight plywood for diode lasers, similar to the “light” Proofgrade plywoods: