Large Cardboard Stencil

My daughter is in competitive dancing and so her studio has a dance number where each dancer holds a silver serving dish that's supposed to look like a large US Dime. They were going to have somebody make vinyl stickers for the details but they were concerned those would too easily peel off (at one point in the dance, they are standing on the trays..). They decided paint would be better, with an extra layer of clear coat to protect it. That would require a stencil. My wife offered that I have a laser cutter and could probably make said stencil. I got volunteered! But that's fine. My wife had to glue on 1000 small jewels on each of 7 costumes so I think I got the better deal.

Problem is, the stencil needed to be some 20" inches or so, and my laser cutter (an xtool M1) can't handle something that large in either x or y dimensions.

So, I had to split it up into four quadrants.

I also had to start from a bitmap image of a dime.

Luckily I have done several things starting from an image to laser cut so I already had a technique to do this, which I will describe here.

Supplies

1. cardboard
2. toothpicks
3. hotglue or other glue
4. desired spray paint

Tools:

1. Hotglue gun
2. FireAlpaca or other bitmap image editor
3. Rapidresizer Image to SVG converter (free!)
4. Laser cutter and software (I used xTool Creative Space with an xTool M1)

The first thing is to find your desired image. You'll want the highest resolution possible here, for the best results. You will also want to find images that are black and white or otherwise have very defined edges. In the next step you can experiment with different images to see what you get, but generally you want as close to a single colour image with clearly defined lines as you can find.

Take this image, and slice it up into 4 equal squares. If those four squares won't each fit your cutter you might have to go smaller, but for me, 4 was good. I used FireAlpaca to do this because I'm all about free software. Save each image with a sensible name with "left-top", "right-top" etc added so it makes it easier to find and place.

I have a front and back so I needed to take the original image, cut it in half, then cut each of those into four quadrants.

You'll most likely need to take your image and make it suitable for a stencil, so you can use this free tool to do that. What it will do is create outlines around the solid parts of your image that a laser cutter can follow. Otherwise, the cutter won't understand what to do with the solid areas and will want to engrave them rather than cut around.

I found a great little free tool called RapidResizer. The previous tool for making the stencil also comes from this site. They have software for sale which you could check out, but I used the free tools.

This will take your bitmap images and convert them to SVG. While it's doing this, it will smooth out the pixels and give you a really nice scalable SVG file. Save each of the four images with this tool.

Now you've got 4 squares you can import into your laser cutting software. My device is an xTool M1 so I used their xTool Creative Space software. After importing each image separately, I put a box around it so it will cut right up the edge of the image so it can line up with the other 3 image cuts.

Then, laser cut each square.

You will want to make sure to remove the stencil outside as well as all the now floating elements that you will need to attach to finalize the stencil. Think about the holes inside of an "O" and things like that.

For all the floating elements you will need to reattach these. I used toothpicks as they are easy to use, thin, and strong. Initially I had thought I would use small strips of cardboard that I would also laser cut, but the toothpick idea came to me afterwards and was much easier. In some areas I did use strips of cardboard, to join the four stencils together.

I used hotglue to attach these as it hardens pretty quickly. You could use any liquid glue but then you'd have to wait a while for it to dry.

Before you paint your final object, do a test print. I found my stencil didn't want to lay flat, so I used a stick that I didn't mind getting painted to hold down areas as a sprayed. Use quick movements so the paint doesn't get too thick and smudge, and always point the spray in the same direction and angle for best results.

In my test print I noticed a few bits that didn't cut off the stencil which caused the words not to show up completely. Glad I caught that before doing it on the final object.

After the stencil spray had dried I did another coat of Krylon clear to protect the print. I did seven of these, both sides.

They performed well! And the prints held up as well.