All About Baltic Birch
Oh, Baltic Birch… the love / hate relationship with the material! Let’s talk about Baltic Birch (BB) and general cutting expectations.
The overall issue is inconsistency in cutting with a laser. It can cut fine then one spot doesn’t go through wrecking the whole project. Why does this happen? The answer is extra glue in certain spots. BB is a plywood which is made in layers. The manufacturer saves the best boards for the outside; the ones that show. The middle layers are not seen, therefore, given less attention. If there is a void in one of the inner layers, extra glue will fill this space.
Baltic Birch is not manufactured for lasers. It is simply made for furniture and other construction and intended to be cut with a table saw, router, or other power tools. So the manufacturer is not worried as much about density or whether a laser will go through it. So if one thinks the glue inconsistency is a reflection of “quality”, that is not totally accurate. Having some voids is a general shortcoming of the material.
We test all of our woods on a Glowforge Basic, with glue voids and all, the 1/4th inch cuts quite well at a speed of 110. It actually cuts well even faster but we slow it to account for the inconsistency. However, this is getting close to the limits of the Glowforge. It cuts, but the mirrors need to be cleaned, correct focus height, and generally optimized machine. 1/4th inch Baltic Birch is not for the faint of heart!
You may want to try 1/8th Baltic Birch if you have difficulty with the 1/4th. Or MDF Core material, while more expensive than BB, do have a more homogeneous core and so cuts more consistently.
Basically, we just want to be upfront with potential pitfalls of this material.