Glowforge Material Notes

A collection of observations from using various, mostly non-Proofgrade, materials with the Glowforge. These are observations based on limited experience, not provably correct claims of fact. Your mileage may vary.

Note: The Glowforge Basic has a lower power output than the Pro. For non-full power settings, the Basic and Pro are supposed to have identical output. Thus, numeric power settings from 0-100 should yield the same results. For cuts on a Basic, you might need to drop the speed ~10% or bump the speed by ~1.6x and do two passes.

Material Settings

Specific Items

Paper Settings

Slots and Kerf

For making parts fit together tightly but still allow disassembly. All measurements taken with digital calipers. Thicknesses may vary between sources.

Material Notes

Birch Plywood (1/8”)

Bulk 1/8” Baltic Birch Plywood from Amazon (Woodpeckers seller) is OK quality; some sheets are warped and there is the occasional plug. It cuts fairly consistently, but occasional spots may not cut through at 250 - they will typically cut through at around 190-200.

Use honeycomb bed holddown pins to flatten warped sheets. They angle into the honeycomb grid and force even warped plywood to lie flat.

Birch Plywood (1/4”)

As plywood gets thicker, there is more opportunity to hide lower quality wood in the middle layers, typically resulting in plugs that won’t cut consistently. Quality varies considerably between sources. If it isn’t cutting through consistently, add passes or slow down the cut (though slower will lead to more edge charring).

Slate

Vary power doesn’t seem to do much on slate. Use patterns or random dots to achieve shading. Craft stores (like Michael’s) often have slate coasters.

Bamboo (Cutting Board)

The settings given produce a relatively light engraving. Lowering the speed or increasing the power will remove a lot of material, which may not be desirable in a cutting board. Multi-pass with lower speed and lower power may produce a darker mark without removing as much material.

The wood grain significantly affects how the laser engraves - you won’t get consistent engraving across the whole surface. If you need uniformity, bamboo isn’t the right choice. However, you can use this inconsistency to your advantage by aligning your design with the grain patterns, though predicting whether a given area will engrave lighter or darker just by looking at the grain is nearly impossible.

Glass Sheets

Many recommend coating the glass with something prior to engraving - typically dishwashing detergent or something non-flammable that washes off easily. Others have had success with transfer paper. With thicker glass, no coating or treatment may be needed.

Note that vary power does not work well with glass. Achieve contrast and shading by using patterns or random dots.

Cardboard

Cardboard boxes are fantastic prototyping material. However, you must keep a sharp eye on any cutting or engraving that takes off more than the outer layer. The corrugation creates air pockets shielded from air assist that can easily become pockets of flame.

Avoid designs with lots of closely spaced cuts. Sharp corners will tend to have burn spots.

Also, cardboard is stinky. Not pleasant campfire stinky, but unpleasant paper fire stinky.

Process Notes

Scoring: Generally, the maximum power for scoring should be below the threshold that will penetrate the material. On the Glowforge, very tightly spaced paths may need reduced power. Paths with sharp corners are the most problematic for burn-through as the Glowforge does not seem to attenuate power as it decelerates and accelerates through corners.

Material Sources

National Balsa

Excellent source for reasonably priced basswood in various sizes and thicknesses.

ACE Hardware / Home Depot

Generally has little to no laser-compatible wood. May have large pieces of slate, rock, or sheets of glass. Home Depot will occasionally have 4x8 sheets of 1/8” plywood of sometimes decent quality that can be cut down.

Michael’s

Limited basswood and baltic birch plywood. Excellent source for card stock and various bits of slate.

Amazon

Prices and quality vary significantly. Bulk materials are often not packaged properly and arrive damaged (bulk cardboard and card stock has been particularly problematic). Woodpeckers has decent 1/8” baltic birch plywood.

Garage Sales

Aquarium glass is fantastic for engravings. A bit of a pain to take apart (use gloves!), but you can often find a leaky one for a couple of bucks.