tools · free · firmware-aware · client-side

Free Material Test Grid Generator for Diode Lasers

A material test grid burns a matrix of small squares on your scrap material — each square at a different speed/power combination — so you see at a glance which settings work best. Pick your machine and material below, set your power and speed ranges, and download an SVG (for LightBurn) or firmware-aware G-code for direct GRBL machines. Free, runs entirely in your browser, no account needed.

before you start

What you need: a scrap piece of your target material (at least 100 × 80 mm is comfortable for a 5 × 4 default grid), plus either LightBurn for the SVG workflow or a direct GRBL connection (LaserGRBL, Candle, etc.) for the G-code workflow.

Configure Your Test Grid

Power Axis — columns (X)

Min %
Max %
Steps

Speed Axis — rows (Y, mm/min)

Min
Max
Steps
Size of each square in the grid. 15–25 mm is typical.

Preview & Download

Set your machine and material to generate the preview.

M4 scales laser power with actual speed — prevents corner over-burn during acceleration. Requires $32=1 in GRBL. M3 uses constant power (use for marking sprays where consistency is critical).
before running G-code

Confirm $32=1 is set, position your laser at the front-left corner of your material and set work origin, then do a dry framing pass. The downloaded file includes a complete safety checklist.

What is a material test grid?

A material test grid (sometimes called a "speed/power matrix" or "burn matrix") burns a grid of small squares onto a scrap piece of your target material. Each row uses a different speed — slowest at the top, fastest at the bottom. Each column uses a different power — lowest on the left, highest on the right. After burning, you can compare all combinations side by side and find the setting that gives you the result you want: cleanest engrave, deepest cut, or sharpest contrast.

This is the fastest calibration method for any new material, new machine, or changed material batch. It eliminates the guesswork of "try one setting, see if it worked, adjust, repeat." One 10-minute burn tells you everything about a 20-setting range.

How to use the SVG output in LightBurn

The SVG download is the easiest workflow for LightBurn users. It imports a labeled grid that you assign laser settings to in the Cuts/Layers panel.

  1. Download the SVG file and save it somewhere you can find it.
  2. In LightBurn: File → Import and select your SVG. The grid appears on the canvas at the correct physical size (in mm).
  3. Select all objects (Ctrl+A) and assign them to your desired layer. Set the layer to "Line" (cut) mode — this traces the square outlines and shows you burn depth and edge quality.
  4. To test different speeds per row, select each row's cells and assign a different layer color. Then in the Cuts/Layers panel set the Speed for each layer to match the row's labeled value.
  5. Position the grid on your scrap material in the workspace. Run Frame first to confirm it fits.
  6. Run the job. After burning, read the axis labels: power on top, speed on the left. The cell where both axes look right is your new baseline setting.

LightBurn tip: LightBurn also has a built-in "Material Test" generator (Laser menu → Material Test). Our SVG is useful when you want to run the same grid in xTool Creative Space, LaserGRBL, or share the file with another machine user.

How to use the G-code output (LaserGRBL / direct GRBL)

The G-code file is fully automated: it burns every cell at its pre-assigned speed and power, in order, without any additional software setup. Every cell is a single square outline — the laser traces the perimeter at the given settings so you can compare burn depth and edge quality across the grid.

  1. Open your GRBL control software (LaserGRBL, Candle, OpenBuilds Control, etc.).
  2. Connect to your machine and open the GRBL console. Send $32=1 and press Enter to enable laser mode. Without this, the laser will fire during rapid moves — which is dangerous.
  3. Manually jog the laser head to the front-left corner of your test material. Set this as work origin: send G92 X0 Y0 (or use your software's "Set Origin" button).
  4. Load the .nc file into your software. Run a dry framing pass first (no laser — in LaserGRBL use "Run Border") to confirm the grid fits within your material.
  5. Confirm focus is correctly set for your material thickness.
  6. Run the file. Total burn time varies — a 5 × 4 grid at typical engraving speeds takes 5–15 minutes.

GRBL laser mode is required. Always verify $32=1 is set before running. Type $$ in the GRBL console and check that parameter 32 reads 1. If it reads 0, your laser fires during all G0 rapid moves, which will burn lines across your material and waste your beam time.

M4 dynamic power vs M3 constant power

The G-code mode selector controls how GRBL handles power during acceleration and deceleration:

  • M4 (dynamic, recommended): Laser power scales proportionally with actual machine speed. At the start of a move when the machine is still accelerating, the laser runs at reduced power. At full speed, it runs at the programmed power. This prevents dark spots and corner burns that happen when the laser dwells at full power during slow acceleration. Use this for most engraving work.
  • M3 (constant): Laser runs at the full programmed power regardless of machine speed. Use this when you need consistent power throughout a move — for example, when applying marking spray to metal, where surface chemistry rather than heat depth drives the result. Corners will be slightly darker.

Reading your test grid results

After burning, examine the grid in good light — angle the material to see depth variation:

  • For engraving: Find the cell with the cleanest, most even mark at the contrast level you want. Too light (increase power or slow down), too dark or charred (reduce power or speed up), rough edges (try higher speed with more power).
  • For cutting: Check which cells cut all the way through. The fastest speed that still cuts cleanly is your target — it minimizes heat and char. For materials thicker than the laser can cut in one pass, run multiple passes; this single-pass test shows you the deepest single-pass achievable.
  • Read the axis labels: Power percentage on top, speed (mm/min and mm/s) on the left. Each cell is labeled with both values in the corner of the square.

Tip: Start your search near the center of the grid, not at the extremes. The center is usually where usable results live. Work outward to understand the range.

Safety reminder

Always test on scrap material. Results vary by material batch, moisture content, laser focus, and machine condition. The settings you find with this grid are calibrated starting points — verify on a small piece before committing to a finished workpiece. Wear OD7+ 450 nm laser safety glasses, run ventilation, and never leave a running laser unattended.

Embed this tool on your site

You're welcome to embed this test grid generator on your laser engraving website, blog, or resource page — free, forever. Copy the snippet below and paste it wherever your host accepts custom HTML. The tool runs entirely in the visitor's browser; no data is sent anywhere.

<iframe
  src="https://lasertinkerer.com/tools/material-test-grid-generator/embed/"
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  style="border:none;border-radius:8px;max-width:820px"
  title="Free Diode Laser Material Test Grid Generator — lasertinkerer.com"
  loading="lazy"></iframe>
<p>Free tool by
  <a href="https://lasertinkerer.com/tools/material-test-grid-generator/">lasertinkerer.com</a>
</p>

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Useful gear for running test grids

Better setup means clearer results. These three things make the most difference:

  • OD7+ laser safety glasses (450 nm) Blue diode lasers at these power levels can cause permanent eye damage instantly — good glasses are non-optional. Look for OD7 or higher at the 445–450 nm wavelength range. Search for OD7+ 450 nm glasses on Amazon ↗
  • Laser engraver honeycomb bed Lifts your material off the base so air flows underneath — essential for clean cuts and prevents the material from scorching on the back from reflected heat. Search for laser honeycomb beds on Amazon ↗
  • Air assist pump Blows a focused stream of air at the cut zone — clears smoke, prevents flare-up, and dramatically improves both cut quality and maximum achievable depth. Makes a bigger difference than a wattage upgrade for most cutting work. Search for laser air assist pumps on Amazon ↗

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See also