Great advice from Stick. I had to search out a lumber supply to find baltic birch. It comes in 5 ft square sheets. I generally pull a piece from below the top piece that hasn't had a chance to warp, even though it is very resistant to warping, it can. Also, if exposed to the sun on the ride home, it will turn yellow, so I keep it covered, and store it out of the sun and keep a drop cloth over it in the garage where I store it. Real Baltic Birch is often shortened to BB.
I have no local source of phenolic coated BB, and have to drive a long way to get it. First piece I bought had been stored badly and wasn't dead flat, so I had to go get another piece. So bring a straight edge of some sort to check for flat. Hopefully you'll find a nearby source. I found the coated stuff at a Rockler store, which is the only woodworker supply place for 70 miles.
Since it sounds like you're fairly new to woodworking, I've attached a pdf of the 18-plus things that helped me accelerate my learning curve. It's long and covers nearly a decade of hard and sometimes expensive lessons. It's long, but has pictures. Hope it saves you some time and money.
The more I do, the less I accomplish.
Last edited by DesertRatTom; 12-15-2019 at 10:52 AM.