GlowForge

Terminology

• GF: Shorthand for "GlowForge". There are two types of GF: basic and pro. They differ in the size of material that can be processed and the power of the laser.
• PG: Shorthand for "Proofgrade"™. PG material is provided by GF and is already calibrated for cut/score/engrave. These notes are for manual (not PG) material on a GF Basic.
• Laser: The 'Pro' version has a 45W CO2 laser. The basic (my version) has a 40W CO2 laser. The laser power impacts the 'Power' setting. (50% of 45W is not the same as 50% at 40W.)
• Speed: Value from 1 to 1000. 30% speed is 300. (The forums sometimes call this "zooms" as it zooms around.)
  
  NOTE: GF changed the scale during their beta period. If you see instructions prior to Aug 2017 that use very slow speeds (e.g., 15 for speed), then it's likely the old scale. Using those slow speeds on the new GF will likely cause a fire.
• Power: Value from 1 to 100. 20% power is 20. With a 40W laser, 20% power is about 8W. (The forums sometimes call this "pews" as in a SciFi laser gun firing "pew pew pew!" You might have someone say "I used 800 zooms and 50 pews." The terms 'zooms' and 'pews' came about because GlowForge doesn't provide units.) Keep in mind, power is not necessarily linear! And the intesity will drop with age (just like any light bulb, but with a laser, you probably have a decade or more before you notice).
• LPI: Lines per inch. Mostly for graphics/engraving. Defaults to 225. Use higher value to prevent rastering.
  At around 300LPI, the engraving dots overlap. 225 is good for draft, but will raster. 340 has no noticable rastering on most materials.
  At super high 1355LPI, you might see numberical error in the rastered graph that looks like a pixel shift. I'd avoid anything over 600LPI.
• Flashback: When the laser cuts through, it may create sparks off the crumbtray's metal. These sparks can create burns, or flashback, on the back of the material. Lowering the amount of power (or increasing speed) reduces flashback.
• Kerf: The laser burns away material. The kerf is the gap created by the laser. More power creates a wider kerf. Some materials melt or burn back (e.g., foam or paper), creating a wide kerf.
  • On really hard material, just assume the kerf is 0.002" (0.05mm).
  • In general, kerf on PG hardwood is about 0.002", and 0.002-0.022" in general.
  • PG Medium Maple has a kerf around 0.008".
  • PG Draftboard has a kerf around 0.002" (use 0.05mm - 0.06mm; 0.05 is barely loose; 0.055mm is good).
  • PG Acrylic has a kerf around 0.002" (0.05mm).
  • Zebrawood, Purpleheart, and other really hard woods have a kerf around 0.002" (0.05mm).
  • For inlays: Take half the kerf from the outside material (small hole) and half the kerf from the inside material (fill hole). Increase the inside/fill material's size by this amount. If the outside material is flexible (e.g., wood) and you want a really tight fit, increase the size of the inside/fill material by another 0.001". For inflexible (acrylic, hardwoods), you might add 0.0005" for a really snug fit.
  • Inlay: Acrylic in Medium Maple: Increase acrylic by 0.020. Using 0.015 can be finger-pressed in but also pops out easily. Using 0.017 can still be popped out. However, if 0.020 doesn't fit in the first time, then first put in 0.017 and then pop it out. That will stretch the hole just a little so the 0.020 fits tightly and will never come out.
  • Inlay: Acrylic in Medium Draftboard: (TBD) Increase acrylic by 0.025. The kerf from draftboard is larger than a hardwood like medium maple.
  
  Yes, kerf is about very very tiny fractions of an inch. But it really does matter. Kerf is the difference between "too loose fit" (and lots of glue) and spending hours with a jewelry file or sandpaper to make it small enough to fit. If you make a fingerjoint box with the right kerf, then you won't need any glue.
• Cut: Cuts through material. Uses a solid laser to vaporize material. Slower speeds create more control (rounder edges), but fast speeds are fine for straight lines.
• Score: Vector lines that don't cut. For example, if 30% power cuts the material, then 15% will score it. AFAICT, this just cuts the power to 50% or 25%. If scoring burns at corners or where circles start/stop, then use a slower speed and lower power. Typically scoring under speed 150 (with appropriate power) won't over-burn at corners.
• Engrave: Etching. Rather than using a solid laser, it appears to pulse "pixels". For soft material, engraving can cut! To cut, try higher LPI (more overlap) and/or slower speed (more overlap). You don't always need to up the power to make it cut; just make it go slower and overlap more. Keep in mind, engraving is always slower than cut/score.
• Dither vs Variable power. When engraving grayscale images, you can either dither or use variable power. Some materials can show a gradient intensity (e.g., foam, paper, wood) -- use variable power. Others only show the presense of the lasered area; this is usually materials that don't cut (metal, glass, plastics, etc.) -- use dithering.
• Painter's Tape (aka Blue Tape): Blue painter's tape is can be applied to cover material. If the material burns (e.g., wood, paper, cardboard), then smoke can discolor the surface. A layer of Painter's Tape stops the smoke from discoloring the surface. However: When it gets heated, the quick-release glue can become like cement on paper. If the laser burns the tape (resulting in wide black areas around the cut), then it may not remove from paper. Use low power when using blue tape. Blue tape also has a thickness (0.005"); it requires a minimum of 1000/3 to engrave through the tape.

After each print, the head will click a few times. Do not start a second print job until after the clicking stops. Otherwise, the user-interface could hang. (Known bug.)

SVG Projects

Generators	Sample Projects
Jigsaw Puzzle Generator Box: Makercase Box: Makeabox Box: Connectionlab Box: jeromeleary Box: Lots more boxes (set kerf to 0.05mm!) Box: Tuck Boxes (manila folders) Box Designer (and more!) Joinery (adds joints) Maze Generator 3D Maze Generator Ruler Generator Gear Generator Fractals on Inkscape Living Hinge Examples	Epilog CraftBundles (SVG) LoveSVG (SVG) Laser settings Wood Types Snowflakes (SVG)

Material Settings: Acrylic

Gray are generic media instructions. Blue background means untested/TBD. Red means DO NOT USE.
Power levels assume a 40W CO2 laser (Glowforge Basic).

There are two types of acrylic: extruded and cast.

Attribute	Cast	Extruded
Strength	Hard/Rigid	Soft
Scratch	Needs sharp/hard edge. Think "soft glass".	Easy to scratch; dust, rubbing against a surface, or just looking at it wrong can leave marks.
Colors	Few options, usually uniform color	More color options and patterns
Cut 0.125"	150/full (Try to match the color. Use PG Clear, PG White, PG Black, and for everything else: PG Red.)	150/100 Different providers may require different settings. Likely to melt back to itself if you don't remove it fast enough.
Cut smell	Mild (open a window)	Strong (window and fan)
Cleanup	Toothbrush removes fine dust	Kleenex removes oily smudge
Examples	Glowforge PG, Tap Plastics, Inventables (solids)	Inventables (two-tone)

Material	Thickness (inches)	Cut (speed/power)	Score (speed/power)	Engrave (speed/power/lpi)
PG Medium Red Acrylic	0.125"	150/Full	125/11	1000/Full/270
Thin Clear Acrylic Tap Plastics Take plastic off! Cover in blue tape.	0.065"	225/full Use cardboard as backing to prevent flashback.	500/20	HD: 800/25 SD: 1000/25
Two-Tone Acrylic Inventibles Take plastic off! Cover in blue tape.	0.125"	150/100	125/10	HD: 800/50/675 SD: 300/16/450 (same as PG Red HD) Lower than 675 loses resolution and pixelates.
Acrylic Home Depot	0.093"	200/full Kerf 0.006" (0.16mm)	TBD	TBD, dithered.

Material Settings: Foam

Gray are generic media instructions. Blue background means untested/TBD. Red means DO NOT USE.
Power levels assume a 40W CO2 laser (Glowforge Basic).

Material	Thickness (inches)	Cut (speed/power)	Score (speed/power)	Engrave (speed/power/lpi)
EVA Foamboard (generic, thin) Michaels, Hobby Lobby "Fun Foam" Use magnets to hold it down! Very light material will move when the fan blows.	2mm, 0.076"	1000/50 or 500/50 May need 1-2 passes. Slower for smoother edges. Melts about 0.025" of material; kerf of about 0.025". Even from the same vendor, each batch and color may have slightly different properties. Don't remove from laser unless you know it is cut (permits redoing the cut if it needs another pass).	500/5 Power 5-10 burns through at start/stop. Power 1-5 is faint. On colored foam, may leave dark spots at start/stop.	1000/10/340 to 1000/20/340, variable power. Use 340 LPI to avoid raster lines. Some material colors result in discoloration; power 1-10 varies the coloring, but 10-20 does not. Power 10-20 just makes it deeper. For grayscale images, use variable power with a max power of 10. For large discolored surfaces, there may be a textured "foam" pattern.
EVA Foamboard (Red)	2mm, 0.076"	See generic.	See generic.	See generic. Discolors to a high-contrast dark red. Variable power from 1-10.
EVA Foamboard (Yellow)	2mm, 0.076"	See generic.	See generic. Burns black at start/stop of score paths.	See generic. Discolors to a slightly darker yellow; low contrast. Variable power from 1-20.
EVA Foamboard (Green)	2mm, 0.076"	See generic.	See generic.	See generic. Discolors to a high-contrast dark green. Variable power from 1-10.
EVA Foamboard (Blue)	2mm, 0.076"	See generic.	See generic.	See generic. Discolors to a high-contrast dark blue. Variable power from 1-10.
EVA Foamboard (White)	2mm, 0.076"	See generic.	See generic.	See generic. Zero discoloration; remains white embossed pattern. May look cool if you fill the embossed area with water colors.
EVA Foamboard (generic, thick)	6.35mm, 0.25"	200/60	500/25
EVA Foamboard Amazon Tiles / TNT Cosplay / Harbor Freight ROLLS. Reference	4-6mm	275/100, 2 passes		1000/60/125, 1 pass
EVA Foamboard Foamies Reference	2-3mm	275/80, 1 pass		1000/60/125, 1 pass
Neoprene foam Hazardous gas! Chlorine	0.85mm / 0.033"	500/65 Kerf is about 0.25mm / 0.01"	Unknown	Unknown

Material Settings: Cardboard

Gray are generic media instructions. Blue background means untested/TBD. Red means DO NOT USE.
Power levels assume a 40W CO2 laser (Glowforge Basic).

I use cardboard to test complex patterns and sizing before making mistakes on high-priced materials like wood and acrylic. Cereal boxes are a great stand-in for veneer, and corrugated cardboard can be used to test any 3mm (PG medium) materials.

Material	Thickness (inches)	Cut (speed/power)	Score (speed/power)	Engrave (speed/power/lpi)
Cardboard box lid	Height 1/2" max	Do not use 'cut' mode because it burns; use engrave mode to cut. Engrave 300/65/225 for thick lines Engrave 300/40/340 for thinner lines Use blue tape to make sharper lines.	Do not score; use engrave.	1000/50/340, Use blue tape to make sharper lines. 800/20/270 (no tape needed!)
Cardboard, cereal box (Use to test veneer)	Height 0.025"	300/50	500/5 - 500/10	1000/10 - 1000/20 340dpi
Cardboard, corrugated (Use to test 3mm materials)	Height 0.16"	200/60	500/5 - 500/10	1000/10 - 1000/20 340dpi

Material Settings: Paper

Gray are generic media instructions. Blue background means untested/TBD. Red means DO NOT USE.
Power levels assume a 40W CO2 laser (Glowforge Basic).

For cutting: Place on cardboard to prevent flash-back.

Material	Thickness (inches)	Cut (speed/power)	Score (speed/power)	Engrave (speed/power/lpi)
Printer Paper, 24lb Magnets to keep from blowing.	0.005"	Cut 200/5 (may require a tug to separate) Engrave at 800/20/270 and it barely will burn through. Engrave 800/15/270 for fine lace cuts. Engrave 800/15/340 LPI for more cutting.	500/2	800/10/270 works really well. The burn looks golden on white paper. (Power between 12 and 14 may burn through parts since paper isn't perfectly even at that fine resolution.)
Paper, Cardstock 100lbs	0.005"	TBD Paper may burn/discolor.	Do not score; use engrave.	1000/2/340 to 1000/20/340 Power 2 can be seen but not felt. Power 4 can be barely felt. Power 0-6 cannot be seen on the back when held up to light. Power 10-20 can be seen on the back when held up to light. Variable 0-20 can be used for images.
Paper, Cardstock	0.005"	Try 200/15 - 200/20 Paper may burn/discolor. Try Engrave at 300/650/340 since it will likely burn through.	Do not score; use engrave.	1000/6/340 to 1000/20/340
Rice paper envelopes	0.01"	Try 500/3, 2 passes Put cardboard between the layers to only cut the front.	Do not score.	TBD: Do not engrave. Or use 1000/1/225 and see what happens.
Manila Folders Ref	Height 0.12"	300/40	Crease: 500/20	1000/10 - 1000/20 340dpi
Canvas Ref	0.125"	Do not cut.	Do not score.	1000/50/225 and see what happens. Reportedly no char or smoke. Also look at "Pencil" settings for passing through paint layers.

Material Settings: Leather

Gray are generic media instructions. Blue background means untested/TBD. Red means DO NOT USE.
Power levels assume a 40W CO2 laser (Glowforge Basic).

There are different tanning processes.

• Vegetable tanning (veg tan) is laser safe, but only gives you natural leather colors. This is great for a laser. After lasering, you can dye, stain, waterproof, etc.
• Chrome tanning is very common and results in a wide range of colors. (If you see colored leather, assume it is chrome tanned.) However, chrome reflects the laser. Do not use! Not laser safe!
• Wet tanning uses chemicals. Wet white, wet blue, etc. yields a semi-finished look. Because these chemicals often use metals that can reflect the laser or release hazardous fumes, they are not safe for lasering. Do not use! Not laser safe!
• Natural tanning uses acid, low temperatures, and low oxygen. (Think "mummification" and "dead body in a bog" -- almost never used.) If you can find it, it should work great for a laser.
• "Pleather" and vinyl are plastic fabrics made to look like leather. Do not use! Not laser safe!

Material	Thickness (inches)	Cut (speed/power)	Score (speed/power)	Engrave (speed/power/lpi)
Leather (veg tan) Tandy Leather	0.1"-0.15"	170/100 (a little too strong, chars+smoke) Clean charring with light water and sand edges (Maybe try 170/50 or 170/80) If possible, engrave first, cover in blue tape, then cut.	250/2 Dark line, no smoke/char	1000/15/195 to 1000/30/195 (very readable; no smoke/char) Visually, 15 is a little lighter than 25. 1000/20/270 (high-res; no smoke/char) Photos: variable power, 1000/20/195 variable 1000/25/170 also works, but you can see pixels

Material Settings: Wood

Gray are generic media instructions. Blue background means untested/TBD. Red means DO NOT USE.
Power levels assume a 40W CO2 laser (Glowforge Basic).

There are two common types of wood: solid and particle.

• Solid: Solid wood can be hard to cut, but really looks nice with score and engrave. Beware of finished woods since the coating may not be laser safe. Coatings could result in fire, hazardous gasses, hard-to-cut, etc. (If you don't know if it has a coating, then assume that it has a coating.)
• Particle: Particle wood (particle board) combines wood fragments with glues and fillers. Cheap particle board may include voids (holes within the board), glues that are not laser safe, and fillers that do not cut. When going cheap, your milage will vary per board; two pieces of the same kind of wood from the same manufacturer may act differently! In contrast, PG particle woods have no voids and are laser-safe.

Material	Thickness (inches)	Cut (speed/power)	Score (speed/power)	Engrave (speed/power/lpi)
Wood (Partical)
Plywood Non-PG varies by vendor! Some use glues or apoxy fillers that are not laser safe or won't cut. Others have voids that can make cutting difficult.		TBD	250/40	500-600/40-50/340
Cork Hobby Lobby, Michaels	0.2" (0.1995") Thicker is fine for engraving.	200/50, 4 or 5 passes Cork is really hard to cut. Slower than 150 causes fire. Faster than 250 doesn't cut deep. Too much initial power causes fire, charring, and smoke stains. Keep it at power 50 or less. Even 200/50 4-passes barely cuts all the way. (Still need to cut/pull apart.) Cutting over an engraved area causes fire and smoke staining. Cut first, then engraved! The problem: Cork is a great insulator. First pass burns the cork and carmelizes the top of what is left. 2nd pass takes more power to get past hard carmelized area. 3rd pass needs even more power. Unless absolutely necessary, don't cut cork with a laser.	300/50	1000/10/225, dithered. Works really well: just burns where the laser hits, no smoke stain. No visible rastering. (No masking tape needed.)
Chipboard, dark Artist hardboard	Height 0.15"	240/full 2 passes Try 180/full	500/full	500/50/340
Wood (Solid)
Material	Thickness (inches)	Cut (speed/power)	Score (speed/power)	Engrave (speed/power/lpi)
PG Medium Cherry Hardwood	0.125"	189/Full	195/12 Double sided will have holes that go all the way through where corners meet.	450/28/450
Bamboo, chopsticks	0.185"	TBD	TBD	225/25/340 Bamboo burns really dark! No masking tape needed.
Baltich Birch, Craft/Popsicle Stick	0.085"	TBD	TBD	600/80/340 Burns really dark! No masking tape needed.
Unfinished Birch Cover in yellow or blue painter's tape	1/8in; 3mm	Use: PG Medium Maple Plywood	Use: PG Medium Maple Plywood	Use: PG Medium Maple Plywood
Pine	Any	TBD	TBD	450/80/125 450/50/225 Grain ridges stand out. Power 50-90 (50 is too light, 100 is overkill)
Hardwoods (Zebrawood, Purpleheart, Yellowheart)	0.12" (3mm) Thicker is fine for engraving.	180/full No thicker than 0.12"/3mm; the laser cannot penetrate any further. Even repeated passes won't go further than 4mm. Too many passes will char. Kerf is 0.002". If you need to cut thicker wood, use a saw.	500/1 leaves a very fine line. 500/50 is a deep line	800/50/450 removes 1/32" -- can be used repeatedly up to 1/8". There will be charring. 800/20/450 is great for drawing. For variable depth, use 800/25/450.

Material Settings: Metal

Gray are generic media instructions. Blue background means untested/TBD. Red means DO NOT USE.
Power levels assume a 40W CO2 laser (Glowforge Basic).

Material	Thickness (inches)	Cut (speed/power)	Score (speed/power)	Engrave (speed/power/lpi)
Anodized Aluminum FUN! Very forgiving of power/speed errors. No smell, no dust. Set on cardboard or use blue tape on back to prevent scratching on crumb tray.	0.1" to 0.01" (uncertified, then use auto-focus)	Does not cut.	Same as engrave! 335/80 works well	335/50/450 for thin coating (low heat) 335/80/450 for thick coating 335/full/340 1000/full/340 for less detail. For very thick coatings, may require two passes. HOT! HOT! HOT! Do not touch when finished. Let it cool off (1-3 minutes for small pieces).
Metal Ref	Any	Does not cut.	Does not score.	Coat with yellow mustard or a paper towl moistened with vinegar (wet, not dripping). Try 250/full, 340 LPI Acid + Laser = Engraving. Leaves a "dark marking" where the laser hits.
Stainless steel etching	Any	Does not cut.	Does not score.	Try 1000/20, dithered. Use 3 coats of dry moly lube.

Material Settings: Other (everything else)

Gray are generic media instructions. Blue background means untested/TBD. Red means DO NOT USE.
Power levels assume a 40W CO2 laser (Glowforge Basic).

Material	Thickness (inches)	Cut (speed/power)	Score (speed/power)	Engrave (speed/power/lpi)
Pencil	0.29", round	TBD	TBD	Most pencils have 2 layers of paint. 1000/8/450 goes through first layer. 1000/25/450 goes through all paint to the wood. Beware of the curvature! You only have about 0.1" height change before the laser fails to focus. On a round pencil, that makes the usable canvas about 0.14" high x length of pencil. Aligning long text on the pencil is difficult!
Stone, Lapidary	TBD	Does not cut.	Does not score.	Try 800/89 225dpi
Denim Ref	Medium weight, height 0.015"	TBD	Does not score.	Try 1000/15 - 1000/125
Denim	Light weight	TBD	Does not score.	Try 8/1000
Plastic pill bottles Plastic "2" ♴ HDPE (e.g., white pill bottles) Plastic "5" ♷ PP (e.g., transparent amber bottles)	0.05" or thicker	Does not cut. Just melts and may burn. Fire hazard and messy.	Does not score.	Try 1000/10, dithered. Reportedly no smell. Smooth surfaces should become rough. Transparent should become opaque.
Plastic credit cards; hotel key cards		DO NOT USE! PVC plastic emits corrosive and poisonous gas.
Glass	TBD	Does not cut.	Does not score.	Try 1000/10, dithered. Try 850/100/340, dithered Coat with a thin layer of dishsoap or masking tape to prevent surface fracturing. The idea is to help dissipate heat.
Glass Tile	TBD	Does not cut.	Does not score.	Try 635/full/340 dithered. Coat with a thin layer of dishsoap or masking tape to prevent surface fracturing. The idea is to help dissipate heat.
LaserTile.com	0.315" or 0.3"	Does not cut.	500/50	500/50 at 225LPI - 445LPI, dithered. Vendor claims 800/100 If too dark, use less power or faster speed. If too light, use more power or slower speed.
Silicon Hard drive platters		DO NOT USE! Reflects CO2 laser. This will damage the laser cutter. May injure you if you are standing near the laser cutter.