DSF

Yes, these are cut from UniSub board.

Aha, it wasn't coasters/placemats I was pressing, it was jigsaws

Sorry for being a numpty

bms;24517 wrote:Yes, these are cut from UniSub board.

Why are they a different colour? UniSub coasters are lightish brown, while wooden coasters are a much darker brown. UniSub coasters have "clean" plain backs, while wooden ones often have scruffy dark patches or white marks all over them.

Does someone take the premium-quality UniSub board and then drag it through a particularly shabby hedge to make the wooden coasters? Do they then go out of their way to make the printable side so much more fragile and easy-to-chip?

Anyone tried the rubber/fabric mousemats for placemats? Should imagine they are machine washable and there'd be no warping problem. Cheaper too.

In my experience, any hardboard / MDF product has the potential to warp when sufficiently heated - however, the likelihood of it warping increases when the surface area is significantly larger than it's depth (this is why you never see coasters warping - surface tension holds it flat). I've occasionally seen the same thing happen with the Chromaluxe Photo panels.

I think (and it is only a theory), that if Unisub were to make these products from a denser hardboard, the issue would lessen (but not entirely disappear) - but you would see an increased material cost as a result.

I have found (only personal experience), that if you weigh these items down immediately after removing from the press and allow them to cool completely before removing the weight, that they're usually fine. Don't be tempted to take the the weight off a little early (like me) - it will warp if even slightly warm!

To the OP: I tend to find 200°C for 60 seconds works better than 185°C/60secs (again, just personal experience).