Laser Power and Speed Settings by Material (Reference Chart)

Almost every settings chart on the internet has the same flaw: it never says which machine it is for. "80% power at 300 mm/min" means two completely different operations on a 5 W diode and on a 60 W CO₂.

This guide gives you two things. First, starting charts split by laser type. Second — and more useful — the method for deriving your own numbers, which are the only ones you can actually trust.

Before the chart: why no number is universal

Four variables change the result even if you copy the settings exactly:

• Real optical power, not the advertised figure. A module sold as "40 W" is usually 40 W of wall draw and 5–10 W optical. The optical number is the one that matters.
• Focus. Half a millimetre out of focus can double your kerf width and halve the effective power at the surface.
• Material is not a standard. Two sheets of 3 mm MDF from different suppliers have different densities and different binders. Plywood is worse: one knot or an internal glue layer will stall a cut that worked a minute earlier.
• Air assist. Blowing air across the cut point clears smoke out of the beam path and cools the edge. Having it or not can be worth 30% in effective speed.

So treat the charts below as starting points, not recipes.

Diode laser (5–10 W optical)

Material	Thickness	Operation	Power	Speed	Passes
Plywood	3 mm	Cut	100%	180 mm/min	3–4
Plywood	3 mm	Engrave	25%	3000 mm/min	1
MDF	3 mm	Cut	100%	150 mm/min	4
MDF	3 mm	Engrave	30%	2500 mm/min	1
Greyboard	2 mm	Cut	80%	600 mm/min	1
Veg-tan leather	2 mm	Cut	100%	250 mm/min	2
Veg-tan leather	2 mm	Engrave	20%	3000 mm/min	1
Black acrylic	3 mm	Cut	100%	120 mm/min	5–6
Paper / cardstock	—	Cut	45%	1200 mm/min	1
Anodised aluminium	—	Mark	100%	800 mm/min	1

Two things specific to diodes:

Clear acrylic will not cut with a blue diode. The material passes 445 nm light almost without absorbing it. Black acrylic works, some dark colours work, but clear needs a CO₂ laser — or the workaround of painting the underside black.

Anodised aluminium is marked, not engraved. The beam burns off the anodised layer and exposes the bare metal underneath: high contrast, zero depth. Real metal engraving needs a fibre laser.

CO₂ laser (40–60 W)

Material	Thickness	Operation	Power	Speed	Passes
Plywood	3 mm	Cut	55%	900 mm/min	1
Plywood	6 mm	Cut	80%	400 mm/min	1
MDF	3 mm	Cut	60%	800 mm/min	1
MDF	6 mm	Cut	85%	350 mm/min	1
Acrylic	3 mm	Cut	55%	550 mm/min	1
Acrylic	5 mm	Cut	75%	300 mm/min	1
Acrylic	3 mm	Engrave	30%	2000 mm/min	1
Leather	2 mm	Cut	40%	700 mm/min	1
Fabric / felt	—	Cut	25%	1500 mm/min	1
Glass	—	Engrave	40%	1200 mm/min	1
Slate / stone	—	Engrave	70%	900 mm/min	1

On CO₂, cast acrylic engraves with a frosted white finish while extruded acrylic cuts with a polished edge. If you want the glass-like flame edge, use extruded and a single fast pass.

Materials you should never cut

This is not a settings problem. These release fumes that damage the machine, your lungs, or both:

• PVC and vinyl — release chlorine, which becomes hydrochloric acid on contact with moisture. It corrodes your optics, rails and electronics, and it is toxic to you. This is the most important entry on the list because adhesive vinyl is so common in workshops.
• Polycarbonate (Lexan) — burns and yellows instead of cutting, and absorbs the wavelength poorly.
• ABS — releases hydrogen cyanide and melts rather than cuts.
• Carbon fibre — the epoxy matrix releases toxic fumes.
• Anything with brominated flame retardants, or any plastic of unknown composition.

If you cannot identify a plastic, do not cut it. The copper wire flame test exists, but it is not worth risking your optics over one part.

Calibrating your own settings in 20 minutes

This is the method that replaces any chart. You need an offcut of the actual material you plan to use.

1. Focus first

No setting matters if focus is wrong. Focus using whatever method your machine has — spacer block, ramp test or autofocus — and leave it alone for the whole test. Change material thickness, re-focus.

2. Run a power/speed matrix

Draw a grid of 10 × 10 mm squares: 5 columns × 5 rows, 25 squares. Assign five speeds to the columns and five power levels to the rows, spanning a wide range around the chart value.

Run the matrix on your offcut. One minute later you have 25 real combinations for your machine on your material.

3. Read the result

• For cutting: the best setting is the fastest one that goes through cleanly. If you have to push the part out, it did not go through.
• For engraving: look for contrast without deformation. If the surface dishes or bubbles, you have too much power.

4. Write it down

Record material, supplier, thickness, power, speed, passes and date. Supplier matters: when a new batch behaves differently, that note tells you whether the problem is the machine or the wood.

Over time that notebook beats any internet chart, because it describes your specific machine with its accumulated hours and its particular tube or diode.

Common problems and what to change

Heavily burnt edges on wood. Too much power or too little speed. Raise speed before lowering power: fast and strong burns less than slow and gentle, because heat has less time to spread sideways. Masking tape over the surface also helps a lot.

Not cutting through even at higher power. It is almost always focus, not power. Check focus before touching anything else. Then check whether the lens is dirty — a film of resin costs a surprising amount of power.

Inconsistent cutting across one part. Usually the material, not the machine — a knot or a glue-rich zone in plywood. If the pattern always appears in the same area of the bed, then it is the machine: the bed is not parallel to the plane of travel.

Acrylic edges come out cloudy. Too many passes or too slow. One fast, powerful pass gives a better edge than three gentle ones.

From design to machine

Once you have your settings, the next step is getting the file to the machine cleanly: closed paths, no duplicates, correct units. That is the other place where material gets wasted.

I cover it in the guide on converting SVG to G-code for laser cutting.

If you would rather skip file prep entirely, MEZ Laser turns an image into cut-ready paths directly in the browser.