<p>The scorch marks in the images provided appear to be condensed wood sap, common with laser engraving. They can be completely eliminated outside of the burn area by using a mask, typically ordinary masking tape. I use sign cutter transfer paper high tack as a mask as it requires less laser power for burn-through.</p>

<p>The scorch marks outside the engraved area is wood sap. The coloration inside the burn area is also wood sap, but is affected by the type of wood.</p>

<p>I've engraved laser-grade plywood, which has a "laser-friendly" concentration of binding glue holding the layers. Using wood that is engineered for routers does not exclude its suitability for laser use, but does not guarantee results.</p>

<p>Another product commonly used with laser cutter/engravers is MDF, which is effectively sawdust and glue. The glue burns/vaporizes and condenses as well.</p>

<p>The type of wood will play a large factor in the coloration. It may be necessary to experiment with various species of wood samples in order to find the red hue you seek.</p>

<p>Lower travel speed of the laser along with appropriate power settings for the desired depth of engraving will provide more sappy burns. Reducing the nozzle air flow with an add-on valve will increase the sap deposited. If you reduce nozzle air flow, do not reduce it to the point where the vapors will travel into the nozzle and fog the lens.</p>

CC BY-SA 4.0
2018-09-27T13:20:45.993Z
be careful with the vinyl transfer paper.  If it made of vinyl (which most are) then it emits chlorine gas when burned.  Chlorine gas can not only hurt you if inhaled, [it can damage the optics on the laser](http://atxhackerspace.org/wiki/Laser_Cutter_Materials)
Henry Taylor
CC BY-SA 4.0
2018-09-27T21:12:58.673Z
That's certainly a valid concern. The stuff I use is paper with a light gum adhesive.
fred_dot_u
CC BY-SA 4.0
2018-09-27T09:31:31.503Z
2018-09-27T21:13:24.703Z
2018-09-27T21:13:24.703Z
fred_dot_u
<p>I'm trying to burn some nametags, but I'm getting inconsistent results.</p>

<p>In the image below, the tag on the right, with the reddish scorch marks, is what I'd like.</p>

<p>The tags on the left, with the uglier black marks, is what I don't want. The different burns come from fiddling with power/speed settings.</p>

<p>In both instances I've used "standard makerspace plywood", so there may be a material difference.</p>

<p>Which leads to my questions:</p>

<ul>
<li>What wood will give red-hued scorch marks?</li>
<li>What settings will maximize such marks?</li>
</ul>

<p><a href="https://i.sstatic.net/bVqpJ.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/bVqpJ.jpg" alt="Nametag image"></a></p>

<wood><woodworking><cutting-machine>
How do I get reddish scorch marks with a laser cutter?
Richard
# How do I get reddish scorch marks with a laser cutter?

(Asked by: username_0 on 2018-09-27)

I'm trying to burn some nametags, but I'm getting inconsistent results.

In the image below, the tag on the right, with the reddish scorch marks, is what I'd like.

The tags on the left, with the uglier black marks, is what I don't want. The different burns come from fiddling with power/speed settings.

In both instances I've used "standard makerspace plywood", so there may be a material difference.

Which leads to my questions:

* What wood will give red-hued scorch marks?
* What settings will maximize such marks?

[![Nametag image](https://i.sstatic.net/bVqpJ.jpg)](https://i.sstatic.net/bVqpJ.jpg)

**Tags:** wood, woodworking, cutting-machine


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## 1 answers

### Answer by username_1 on 2018-09-27. Score: 4

The scorch marks in the images provided appear to be condensed wood sap, common with laser engraving. They can be completely eliminated outside of the burn area by using a mask, typically ordinary masking tape. I use sign cutter transfer paper high tack as a mask as it requires less laser power for burn-through.

The scorch marks outside the engraved area is wood sap. The coloration inside the burn area is also wood sap, but is affected by the type of wood.

I've engraved laser-grade plywood, which has a "laser-friendly" concentration of binding glue holding the layers. Using wood that is engineered for routers does not exclude its suitability for laser use, but does not guarantee results.

Another product commonly used with laser cutter/engravers is MDF, which is effectively sawdust and glue. The glue burns/vaporizes and condenses as well.

The type of wood will play a large factor in the coloration. It may be necessary to experiment with various species of wood samples in order to find the red hue you seek.

Lower travel speed of the laser along with appropriate power settings for the desired depth of engraving will provide more sappy burns. Reducing the nozzle air flow with an add-on valve will increase the sap deposited. If you reduce nozzle air flow, do not reduce it to the point where the vapors will travel into the nozzle and fog the lens.

> **Comments:**
> **username_2**: be careful with the vinyl transfer paper.  If it made of vinyl (which most are) then it emits chlorine gas when burned.  Chlorine gas can not only hurt you if inhaled, [it can damage the optics on the laser](http://atxhackerspace.org/wiki/Laser_Cutter_Materials)  
> **username_1**: That's certainly a valid concern. The stuff I use is paper with a light gum adhesive.  

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