Speed vs. precision

The core trade-off

Every laser job involves a balance between how fast the head moves and how much power it delivers to each point on the material. Get this balance wrong and you get scorched edges, incomplete cuts, or mushy detail.

Understanding the relationship between speed, power, and focus gives you control over your results — and the ability to fix problems when they appear.

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Speed and power work together

The laser beam affects the material by delivering energy. That energy is a function of two things:

• Power — how much energy the laser emits per unit time
• Speed — how quickly the head moves across the material

If you double the speed, the beam spends half as long at each point, so each point receives half the energy. To compensate, you'd need to double the power — or make two passes.

This means there's no single "correct" speed or power — it's the combination that determines how much energy your material receives.

A useful mental model: think of the laser as a paintbrush. Speed controls how fast you drag it; power controls how wet the brush is.

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When to optimise for speed

Speed matters most when:

• You're running production batches — engraving 50 identical items
• The job has large filled areas to engrave (backgrounds, logos, large text)
• Material detail isn't fine — large text, simple icons

For high-speed engraving, the key settings to adjust are:

• LPI (Lines Per Inch): Lower LPI (150–250) means the scan lines are spaced further apart. Jobs run faster but with less density — ideal for large fills
• Power at speed: Run the highest speed your machine can maintain cleanly, then dial power up until results are good. Avoid slowing down more than necessary

Modern gantry machines (like the xTool P2 or Sculpfun S30) can engrave at 1,000mm/s+ with excellent results when dialled in correctly.

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When to optimise for precision

Precision matters most when:

• You're engraving fine detail — small text, intricate patterns, photographs
• The material is delicate or easily scorched
• You need consistent depth (e.g. relief engraving, 3D surface texturing)

For precision work:

• Higher LPI (300–600+) gives denser, finer scan lines. Jobs take longer but produce sharper detail
• Lower power + slower speed gives more control over depth and prevents burning
• Defocus slightly for photograph engraving — a slightly defocused beam produces softer gradients that look better in greyscale photos on wood

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Finding your settings: test tiles

Don't guess — run a material test. Most laser software (LightBurn, xTool Creative Space) includes a test grid generator that runs a matrix of speed/power combinations on a small area.

From a single test tile you can read off:

• The minimum power needed to cut through
• The optimal speed/power for engraving without burn
• How the material behaves at extremes

Keep a notebook (or a folder of saved LightBurn files) for each material type and thickness. Once you have good settings for 3mm birch ply, you'll never need to test it again.

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Focus — the often-overlooked variable

All of the above assumes your laser is correctly focused. Even 1mm of defocus significantly reduces power density, producing weaker results or blurry detail.

• For cutting: focus at the top surface of the material
• For engraving: some users prefer to defocus 1–2mm above surface for softer gradients
• For acrylic cutting: some prefer focusing slightly below the surface to improve edge quality

Autofocus probes (standard on many modern machines) remove the guesswork, but it's worth understanding what they're doing and verifying occasionally with a manual focus check.

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Quick reference

Goal	Speed	Power	LPI
Fast batch engraving	High	High	150–250
Fine detail engraving	Medium	Medium	300–500
Clean cutting	Medium-low	High	N/A
Photo engraving on wood	Medium	Low–medium	300–400

These are starting points only. Material, machine, and ambient conditions all affect results — your test tiles are your best guide.

Looking for a machine with the right speed and work area for your needs? Browse and filter lasers to compare specs side by side.