Glowforge Interface - Vector Files Made Easy šŸ¤”

Itā€™s soooooo easy to create files easily in programs like Illustrator, Inkscape, CorelDraw and Affinity Designer if you understand what the Glowforge interface sees when it looks at your file.

(Think of this as a last batch of Tips and Tricks, then Iā€™ll quit bugging you.) :wink:

Iā€™m going to demo in Illustrator again, but the same things will be done in whatever program you choose to use for your designs.

If you have questions about specifics for other kinds of drawing and modeling software, some of the customers here put together a Matrix that gives little quick reference mini-tutorials on how to perform specific tasksā€¦itā€™s an easy way to find what you need without sitting through hours of videos. (And scroll down in the list for other hidden goodies.)

2D Vector Design Programs Matrix

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And awaaaay we goā€¦ :grinning:

How to Create Cut and Score Lines in your File:

Cut lines are easy, all you do is create a vector shape or a line, and give it a stroke color. If you give different lines different stroke colors, they will be set up as separate Cut jobs in the interface.

(Expert tip: Leave any closed shapes empty (no fill color) for your Cut and Score lines, but use a different color for the Cut lines as opposed to the Score lines. The interface will interpret those correctly, assign a Cut operation to each group of lines, and you can convert the separated cuts to Scores in the interface.)

If there are no fill colors in the shapes, the interface interprets the saved SVG file correctly, with 3 Cut operations offered. You can use the shapes in the thumbnails to see which operation attaches to which sets of lines on the bed, or if they are all similar, hovering the mouse over a thumbnail causes the impacted shapes and lines to turn blue on the bed.

Convert the Blue Wavy lines to Scores by clicking on the thumbnail, then clicking at the top of the popout to choose Score instead of Cut.
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How to Create Vector Engraves in your File

The Glowforge interface interprets vector Fill colors in shapes as Engraves. The best way to create an engrave is to use just a Fill color without putting a stroke color on it. That clearly indicates to the interface that you want that part to be engraved.

If you want to have separate engraves in a file, you can set up different fill colors, just like you do with different stroke colors for separate Cuts.

Letā€™s take a look at what happens when several different vector engraves are submitted to the interface. Four engrave shapes are shown below, two of them with fills but no stroke color, the other two with both fills and stroke colors.

The results of the interpretation by the GFUI are shown below. You can see that for the two stars that had strokes applied along with the fill, the GFUI will default to a cut instead of an engrave. You can convert these back to an engrave, but you canā€™t use the stroke as a score, and engrave the fill, if the two parts are attached. You just get one operation assigned to the shape.

If you want to have both an Engrave and a Score operation set up on the same shape, duplicate the shape in the same spot, set one up with a Fill (only) and one with a Stroke (only).

Note: If you thought you created an Engrave, and it shows up in the GFUI as a Cut, it probably means you left a stroke color applied to the filled shape. (Itā€™s easy to overlook a similarly colored or small sized stroke line.)

The Trouble with ā€œTribblesā€

(Actually the trouble is with special types of engraves that I call ā€œIsland Fillsā€ but Iā€™m a fan of the Trek.) :wink:

Itā€™s easy in drawing programs like Illustrator to create a design with different colored fills that has white fill on top of some other color. The white fill looks like a hole, but itā€™s not.

Say I wanted to engrave a star shaped ring on something, and I created a couple of stars in Illustrator and line them up and center them. I give both stars fill colors but no strokes, and put the white one on top of the blue one, so it appears to be the ring shape that Iā€™m looking for.

What it actually is though, is a larger blue filled star with a smaller white filled star sitting on top of it, and the interface is going to see it as a solid block of engraving. For vector engraves, the Glowforge interface interprets any fill color as something to be engraved, even if it is filled with white.

My logic for calling it an ā€œisland fillā€ issue, is that it occurs any time you have one color completely surrounded by another color, like an island.

Okay, so in order to keep from making a mistake in your design, just turn on the background grid. You can see the potential problems pop right out at you.

If you want to subtract the front shape from the rear shape in order to make an actual ring for engraving, select both shapes, use the Pathfinder palette and click the Minus Front tool. That punches the top shape down through the bottom shape and subtracts it out, turning the resulting shape into a Compound Path, and it tells the Glowforge interface exactly what you want it to do.

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(There are similar tools in Inkscape, CorelDraw and AffinityD, and the removal of ā€œislandsā€ needs to be performed as a subtraction or difference in each design program. The GFUI interprets any vector fill color that it sees as something to be engraved, even white, so we have to subtract it out if we donā€™t want it engraved. It should be noted that CorelDraw and Affinity Designer users might encounter a problem doing this due to a Fill Rule treatment that is unique to those programs. The easy method for correcting the output for this is outlined by @kennyb here: How to Handle the Fill Rule . Other tutorials specific to the various design programs are available in The Matrix if needed.) :slightly_smiling_face:

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Using Text in your Vector Files

Text needs to be converted into Outlines or Paths before being brought into the Glowforge interface. It will be interpreted as an Engrave.

Fortunately most of the drawing programs allow you to select the option of converting your text to outlines automatically in the SVG saving settings. (Weā€™re still trying to find the one for Inkscape, but apparently it has the ability as well.)

The drawing programs also each have a manual method of conversion (listed in the Matrix), and the SVG settings suggested in the tutorial listed here already have the correct settings shown when we know them, so make sure to reference it before saving your SVGs.

Correctly Save a File as An SVG for the Glowforge
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Using Vector Gradients in your Files

GrooveStranger asked a question below about vector gradients in the comments that I forgot to mention here initially ā€¦the Glowforge interface (currently) does not treat vector gradient Fills as variable depth grayscale engraves, which is pretty much what we want to use them for. (The darker the color, the deeper the engrave is going to cut.) That function currently is only performed on bitmap style images.

For these, we can rasterize the gradients and have them perform as designed. Just select your gradient Fill, click on Object > Rasterize and select a ppi value. (Bitmaps that you create in the program are already embedded.)

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Using a Bitmap (Raster) Image in your Vector File

The Glowforge interface treats bitmap or raster style images slightly differently than vector engraves. Bitmaps and other images consisting of pixels are treated as engraves by the interface. White is ignored when the interface interprets bitmap images for engraving, and other colors are given a grayscale interpretation.

If you want to use the bitmap image with other design elements, it helps to Embed the image into the file. That includes a copy of the image in the file itself, and you donā€™t have to keep a separate Linked file for it.

To embed a bitmap image in Illustrator - drag the file onto the artboard, and click the Embed button in the top row while the image is selected. (Youā€™ll also want to make sure that Embed Images is selected in your SVG settings when you save the SVG file from AI.)

When the Glowforge interface sees a bitmap image embedded in a vector SVG file, it processes it separately from other bitmap images. So if you have three bitmaps embedded in your file, you will get three engrave operations.


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A Couple of Very Important Thoughts about Bitmap Image Sizes and Resolution

I am using the term ā€œbitmapā€ in this writeup to mean any type of image that consists of pixels, as opposed to actual bitmap images. Iā€™m not even sure the GFUI can handle actual bitmaps yet.

In actuality, for the Glowforge interface purposes, you will want to use Jpegs or PNG files.

When you are choosing a resolution for your engraved images itā€™s very easy to confuse the term ppi (pixels per inch) which the Jpegs and PNG files use, with the term LPI (lines per inch) which the laser uses.

Using a tremendously high pixel value in your images makes ink printed photographs look stunning, but I find itā€™s totally unnecessary in laser engraving, and too much data from high pixel count is one of the things that can cause a file to hang up in the buffer. (ie: Unspecified Error Message.)

So I try to keep the pixel count in my Jpegs and PNGs to 300 ppi or less. (The interface can handle 600 ppi, but it adds processing time, and unless Iā€™m engraving on a grain of rice, I donā€™t really need the pixels to be that small. So I keep the higher resolution images for the little stuff.)

Internet images are generally set at 72 ppi, and they engrave just fine on the Glowforgeā€¦you donā€™t need really teeny tiny pixels.


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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.
(Havenā€™t measured itā€¦canā€™t prove itā€¦itā€™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 youā€™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 youā€™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, youā€™re going to get a ā€œcrisperā€ 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 youā€™re going for.

Converting a Bitmap (Raster) Image into a Vector Image

You can use your drawing programā€™s native Auto-Trace function (sorry AffinityD users, you donā€™t have one yet) to rescale smaller bitmap images into something larger without introducing raggedy edges from pixelization.

They generally give you more control about how the results turn out, and there are tips in the Matrix for how to use them in the various programs.

The one thing you want to remember when using an Auto-Trace program in one of the drawing programs is to check the little box that says Ignore White when you are doing the trace.

(This is an Illustrator thing - not sure if itā€™s an issue with Inkscape and CorelDraw.)

If you leave that box unchecked in Illustrator, youā€™re going to generate a whole lot of duplicate information. If you check it, white areas will get punched out of your raster image correctly.

Remember that in vector engraves, white fill is just another color. You actually want to remove it when you vectorize your image for engraving in the Glowforge.

In the ancient CS versions of Illustrator, the Ignore White option is hidden deep in the Live Trace options panel.

And hereā€™s where it is in the newer versions:

New_AI_ignore White

Donā€™t forget to check the boxā€¦It will save you a whole lot of grief. :wink:



Okay, thatā€™s about it. Several easy concepts to remember when you put your files togetherā€¦the rest is just getting comfortable with it.

Go make something cool. :grinning:

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Wow, great writeup! And I love your demo art!

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Awesome! Your description of LPI vs DPI is especially helpful. Iā€™ve had the idea for a while that thereā€™s a maximum effective LPI for a given material. Same idea (I think) as printing photographs, thereā€™s usually no reason to scan artwork at 1200 DPI if your printer can only handle 150 or 300 DPI (dating myself again). Likewise no reason to attempt to engrave paper/bamboo/ā€œsoftā€ things at 1000+ LPI, as <300 is probably a better match.

Iā€™ve been thinking of it as the maximum information density for a given material, but I like your description much better.

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Wow! A treasure trove of goodness! Thank you.

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I dunno man, information density spells it out for me.

Great post Jules! Ties a lot of stuff together, in a broad stroke. :purple_heart:

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Thanks so much for the time that youā€™ve put in to all of these tutorials. They have been (and continue to be) immensely helpful to me.

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Inkscape also has a setting that converts text to curves on saving.

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Okay greatā€¦Iā€™ll fix that tomorrow. :smile:

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Someone else posted the setting in the past week. If you canā€™t find it Iā€™ll fire up Inkscape tomorrow when I get back to my PC.

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That would be cool. Iā€™ve looked all over Inkscape and canā€™t find it. I know how to convert text to paths but to do it automatically eludes me. I remember someone posting how to do it with AI last week.

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Your posts are so great! Iā€™ve been using Illustrator since the Illustrator 88 days (did I just date myself?) and I always find some great tips or reminders in your write-ups. I guess Iā€™ve trained myself so well to look for object fills I completely forgot about using the grid! When I read that, it was like a ā€œduhā€ giant light bulb went off. I so appreciate your insight and perspective. :sunglasses:

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Iā€™ll dig in tomorrow.

I have an old python script that does it (texts2paths.py - open source on GitHub). But itā€™s one more step after the save. Thereā€™s an auto convert buried in there I think though.

An Inkscape autoconvert upon save would be great. I havenā€™t been able to find it yet.

And fills in so many detailsā€¦ (sorry for the pun, couldnā€™t help myself)

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Maybe steer people away from JPEG? Theyā€™re just going to get weird artifacts.

Absolutelyā€¦Jpegs and PNG files should definitely be checked for artifacts prior to use, and cleaned up if needed.

Not going to try to steer anyone one way or the other though, we can use both, and I use more jpegs than pngs. - I really just want folks to understand how the interface interprets what we send it in this writeup. :slightly_smiling_face:

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This is great in theoryā€¦ but you really get into a whole 'nother realm when suggesting just one file type. For example, I have a JPEG that I really want to use and the general advice is PNG, so I resave as PNG - those heavily compressed web graphic JPEG artifacts translate into a JPEGā€¦ the PNG conversion doesnā€™t know any better. Then itā€™s, ā€œI am using PNG like suggested but getting weird artifacts. Why?ā€

Thatā€™s the thing about this technology - you can use it with just a little knowledge and get pretty good results. The more knowledge you have though, the better those results are going to be.

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If you use a gradient fill inside a shape, does the engrave vary engrave depth as if you had tried to engrave a bitmap? It would be nice if we could design 3d engraves with tools in Illustrator & friends.

A gradient fill by itself wonā€™t work if you save as SVG, but if you rasterize or export to a bitmap format, it will work. You can also select the object and ā€œexpandā€ which will convert things like gradients to individual shapes. That might produce a very complex file, though.

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Thanks!