Introduction
Is slowing down your laser engraver the secret to better results? A lot of hobbyists assume that lower speed automatically means higher quality: darker burns, deeper engraving, and sharper detail. In theory, that makes sense—slower speed means the laser spends more time on each spot, so it dumps more energy into the material.
But in real life, going too slow can backfire hard. You can end up with scorched wood, melted acrylic, warped edges, and details that look “fat” or blurry because the heat spreads. Go too fast and your engraving might be faint, shallow, or incomplete. So the real answer is: slower speed is not always better. It’s about finding the best speed for your laser, your material, and the look you want.
In this article, we’ll break down how engraving speed interacts with power, machine type (diode vs CO₂), and different materials like wood, acrylic, metal, and fabric. You’ll learn when slowing down helps, when it hurts, and how to find the sweet spot without wasting hours on trial and error.
Speed, Power, and Quality: What Speed Actually Controls
Laser speed is basically “how fast the laser head moves.” That one setting controls dwell time—how long the beam stays on each point of the material.
- Slower speed = more dwell time = more heat per spot = deeper/darker engraving.
- Faster speed = less dwell time = less heat per spot = lighter/shallower engraving.
Here’s the big thing many people miss: engraving depth and darkness depend on total energy per area, not speed alone. You can often get very similar results with different combinations, like:
- Slower speed + lower power
- Faster speed + higher power
So if your engraving looks good at a faster speed (with the power adjusted), there’s no bonus prize for making it slower. You just spent more time to get the same result.
Diode vs CO₂: Why “Slow” Means Different Things
Your laser type changes everything. A speed that’s “fast” on one machine can be “slow” on another.
Diode lasers (common hobby machines)
- Typically lower power output (often 5W to 20W optical).
- Often require slower speeds to deliver enough energy for darker/deeper engraving.
- High speeds can reduce detail if the machine can’t accelerate smoothly on tight curves or tiny features.
CO₂ lasers
- Often much higher power output (40W+ is common).
- Can run much faster while still engraving deep or cutting efficiently.
- Better suited for production work because speed doesn’t destroy results as quickly.
Bottom line: A diode user often slows down because they need to. A CO₂ user often speeds up because they can. But even with a CO₂, “max speed always” isn’t a thing—materials and design detail still set limits.
Material Reality Check: Wood, Acrylic, Metal, Fabric
This is where “slower is better” really falls apart. Different materials react differently to heat.
Wood
- Slower speed gives darker and deeper burns (great for contrast).
- Too slow can create heavy charring, soot, and wide burn halos.
- If you want cleaner engraving with less burn, you often need faster speed and adjusted power.
Also: for cutting wood, going extremely slow often increases charring. Sometimes multiple passes at a slightly higher speed give a cleaner edge than one brutal slow pass.
Acrylic
- Slower speeds can increase depth and make edges smoother (especially on CO₂).
- Too slow can overheat acrylic and cause melting, goo, or warped edges.
- Faster speeds can reduce melting but might leave lighter engraving or rougher cuts if too fast.
Important note for diode users: clear acrylic usually doesn’t engrave well with typical blue diode lasers, regardless of speed.
Metal
- Most hobby diodes and CO₂ machines do not “deep engrave” bare metal in a meaningful way.
- If you’re marking coated/anodized metal, higher speed can be better to remove coating cleanly without overheating the metal.
- If you’re using a marking spray, you often need slower speeds to bond the mark properly.
Fabric
- Slower speed is usually a bad idea.
- Fabric burns or melts fast, so you typically want high speed + low power.
- Going too slow can scorch, cut through, or set it on fire.
What Slower Speed Actually Changes (Depth, Contrast, Detail, Heat)
Depth
Slower speed increases energy per spot, which can increase depth. This helps when you need a deeper carve, especially in wood. But for truly deep work, multiple passes are often cleaner than one super-slow pass, because they reduce overheating and allow debris to clear out.
Contrast and darkness
On wood and leather, slow speed often makes the engraving darker because the material gets “baked” more. This is great for bold text and strong contrast. But it can also create soot and smoke staining, which then needs cleaning.
Detail and sharpness
Moderately slower speed can improve detail because the machine tracks curves and tiny shapes better. But extremely slow speed can blur detail because heat spreads and lines get thicker than the design intended.
Heat damage
This is the big downside. Too slow can cause:
- Charring and soot (wood)
- Melting and warping (acrylic/plastics)
- Burn-through or flames (fabric/paper)
- Discoloration or heat tint (some metals)
When Slower Speed Helps
- You need more depth and faster settings aren’t enough.
- You want darker contrast on wood or leather.
- Your design is detailed and high speed causes wobbles, missed details, or rough edges.
- Your laser is underpowered for the material, so slower is necessary to get any mark at all.
When Slower Speed Hurts
- You’re getting charring, soot, or burn halos on wood.
- You’re melting acrylic or getting gooey edges.
- You’re working with fabric or thin materials where heat builds instantly.
- You’re wasting time because the engraving looks the same at a faster speed with adjusted power.
- Overburn is killing detail (fine lines become blobs, small text fills in).
How to Find the “Sweet Spot” Without Guessing
If you want the quickest path to good settings, do this:
- Run a small test grid (speed vs power) on the same material you’re using.
- Pick the fastest speed that still gives you the depth/contrast you want.
- If it’s too dark/burnt, increase speed first before dropping power too much.
- If it’s too light, reduce speed slightly or add a pass.
- For deep jobs, prefer multiple passes instead of one super-slow pass.
This approach saves a ton of time and prevents “random settings” frustration.
Conclusion: Is Slower Always Better?
No. Slower speed can improve depth and contrast, and it can help with fine detail up to a point. But slower also increases heat buildup, which can cause charring, melting, warping, and detail loss.
The real goal isn’t “always slow” or “always fast.” The goal is:
Use the fastest speed that still gives the quality you want.
Once you treat speed like a tool (not a rule), laser engraving gets way easier and way more consistent.
Optional Products on Amazon.co.uk
If you want to see products on amazon, here are search links: