You mean this from the June email? The warranty is a quick read.
New: Proofgrade™ warranty
We have another new announcement: Proofgrade materials are covered under a Glowforge limited warranty as well. This means that your $150 bonus pack of Proofgrade and any other Proofgrade materials you buy (for example, with you gift certificates) are covered too.
We’ve sourced the highest quality materials for our Proofgrade line, so we feel confident backing your materials up with this additional guarantee.
You can read the details at https://glowforge.com/warranty.