The team has been working hard to get materials in place and I’m sorry you haven’t seen them yet! They haven’t given me a precise date, but I do expect to see more and more materials soon.
Adding to what others have said:
Using non-Proofgrade materials does not void your warranty, but if there is a problem with your materials that damages your Glowforge, the damage caused by your materials would not be covered under the warranty. The full details of the warranty are available at https://glowforge.com/warranty.
And, while you wait for us to replenish: if there’s a Joann near you, they may have the Proofgrade materials you want in stock, and many locations are offering curbside pick-up.
In addition, your Glowforge can print on many materials, as long as the supplier can confirm for you that it is laser-compatible. We’ve heard of customers purchasing at Inventables, Johnson Plastics, TAP Plastics, Lowes, and Home Depot. Please confirm with the supplier you choose to ensure it’s laser-compatible, though, as we aren’t experts on other companies’ products.