When i got my light plywood, the core was visibly different than the medium, which is what i mostly use. After cutting it was also a different color.
The core looked more like what i would find in baltic birch.
My thick walnut had a solid core that looked just like mdf, but the board itself was much lighter than the medium plywood (And easy to cut through). But you’re right, the description says hardwood core for light and thick, so it must just look like mdf. Even the photo in the shop of it cut looks like mdf to me.
@remigi you might have luck with the white board. I don’t know how that one would look, you can test a small piece, but this is how mine looked. The engrave was a very solid dark brown that didn’t fade over the course of a few years. We still have that sign. I didn’t seal it or paint it and it hung in our hot garage since that post.
Also, i don’t know about the foiled wood. From what i read it seems like it’s printed paper and coated with polyurethane.
Do you have a local cabinet maker or lumber yard? Cabinet makers often use woods and veneers that are nice to cut and engrave. They may have scraps you can try too.
I’m in Japan now, and although i am still waiting for my glowforge to be delivered, i found lots of wood and mdf to cut here from my local tool shop. The wood is veneered plywood. The mdf looks like what i but in the US, except them even have thinner sizes like 1.5 and 2mm. I only bought proofgrade products to use for designing catalog files.
If mdf is what you have, you can add veneer yourself and seal it too. But if you just want to paint it, I’d follow some of the suggestions above on how to make it absorb less paint. Or you can look for hardboard-it’s mdf, but finished so it is smooth. The paint doesn’t soak in as much, but depending on the manufacturer, it might be harder to cut through.