Manual settings on the Glowforge Dashboard

Let’s talk about using Manual settings on the Glowforge Dashboard! On our website we have a link to all of our Glowforge recommended cut settings, https://craftcloset.com/blogs/news/recommended-cut-settings, but we don’t have recommended engrave settings. Engrave settings are subjective to what you want your engrave to look like. There is a lot to go into deciding what settings to use. If you use the Glowforge preset settings for wood engrave, they are usually set in Draft Graphic, SD Graphic (Standard Definition) or HD Graphic (High Definition); or Draft Photo, HD Photo, 3D Photo, or Deep 3D Engrave.

There is a lot to cover when talking about engraving so in this article we will cover Graphic settings.

Draft Graphic is usually speed 1000 power 100 LPI 195.

SD Graphic varies depending on how thick your wood is. It is usually speed 1000 full power LPI 270. Or speed 535 power 70 LPI 270.

HD Graphic is also depending on thickness and density of the wood. It is usually speed 400, power 51 LPI 450 or speed 300, power 11, LPI 450.

So how do you decide which to use. If you have a small area available on your piece of wood, engraving a small shape at different settings is a great idea to see how each looks on your piece of wood.
Let’s break it down a little further though so that you have more information on what settings to choose.
What Speed and Power should I use?
Glowforge Support has a good article about using Manual settings.
In this article they explain Speed like this:

Speed

Speed controls the maximum speed at which the laser head can move around the printable area

How does this affect my print?

• Increasing speed decreases your overall print time, as the laser head can move more quickly around the printable area.
• Increasing speed decreases the depth of engraves, cuts, and scores, as the laser has less time to impart laser energy into your material.
• Increasing speed reduces the quality of a print. In the case of an engrave, the laser has less time to make an accurately positioned mark on your material. In the case of a cut or score, too much speed can result in the laser head jerking when changing direction, causing jagged lines and bumps in your print.
• Too much speed when cutting and scoring can also result in dark corners when the laser head changes direction. This is due to the additional laser energy put into the material during the between the the rapid acceleration and deceleration of the head.

In this article the explain power like this:

Power

Power controls the maximum amount of laser energy imparted to your material

• How does this affect my print? - Setting higher power levels allows more laser energy to be put into your material, causing your engraves, cuts, and scores to be deeper.
• - Using higher powers than necessary can reduce the amount of detail in an engrave, as the laser energy can damage the surrounding area.
• Precision Vs Full Power The amount of power produced by the laser tube can vary in use. We offer two levels of power control, to maximize both cutting efficiency, and ensuring high quality prints:
• Precision power, as the name suggests, is precise, consistent, and lower in power than the maximum possible output of the laser tube. It’s ideal for cutting and engraving delicate materials such as paper, or when you require a very detailed print result.
• Full power allows the Glowforge to put more power into your material, whilst sacrificing some consistency. This makes it perfect for cutting, where we’re concerned with the laser going through the material, rather than engraving or scoring to a consistent depth.

https://support.glowforge.com/hc/en-us/articles/360033633574-Working-With-Manual-Mode

What is LPI? I found a great explanation of LPI on the Glowforge Community Page. It was written by Jules. They say this:

The LPI (lines per inch) number that shows up in the Glowforge interface is a measure of how many times the laser head is going to move back and forth over a particular area as it fills in solid areas of engraving. There is a sweet spot where it just covers everything with engraving, with no gaps between the lines, and no banding, and that seems to be in the 195 - 225 LPI range.

(Haven’t measured it…can’t prove it…it’s a subjective call. Feel free to run your own tests.)

When you start getting into higher LPI densities, the laser starts cutting over areas it has already cut, so the engraving gets darker and deeper. But it also increases the amount of time necessary to process the engrave with each increase in LPI, and I believe it also increases the amount of movement code that gets written to the file that gets sent back down to the Glowforge. So higher LPI settings will also frequently cause the file to hang up with an error message, especially if you are trying to print something that covers a large area of the bed.

The good news is, recent changes to the interface give us a way to deal with large surface area engraves. If you are engraving something that covers over about half of the bed in height, you can use the Draft Graphic (195 LPI) or Draft Photo (175 LPI) default settings that Glowforge provides, as opposed to the High Def settings, and the engrave will process without hanging up. You will still get complete coverage.

People familiar with doing Print work of any kind might find this hard to believe, since high definition is usually needed to get good photographic results, but you’ll do yourself a tremendous favor by speeding up the time it takes to process the engrave if you keep the LPI at or below 225, and you’re not going to sacrifice quality on large area engraves*.

*Caveat: As with all things in life, there are a couple of exceptions to this that are material related. When engraving on metals like anodized aluminum, tiles or other hard non-porous surfaces, you’re going to get a “crisper” result with a higher LPI value. For those I like to use the HD engrave setting. But you can just do an experiment or two to decide which look you’re going for.

Jules Glowforge Community Post https://community.glowforge.com/t/glowforge-interface-vector-files-made-easy/14351 

So now you have the basics to get started choosing your own settings for engraves. Play around with different settings until you decide what you like for your projects!