This summer our neighbors introduced Lara and me to Rummikub, which despite the weird name turns out to be a super-fun game played with a set of 106 tiles numbered 1-13 in four colors/suits plus two jokers. Tile games like this should be as nice to look at as they are to play — but our friends’ set is this awful 1990s sickly off-white plastic pile of junk, with jokers that looked like evil scary clowns. Ew. I set out to design something better on the Glowforge, sure I’d have it done in a few hours.

A few months later and I finally have something I’m mostly happy with. It’s not an incredible heirloom treasure — but it is nice and we’ll have a good time playing it. I learned a bunch of new techniques, and I suppose it’s healthy for the universe to put me in my place every once in awhile. Hopefully you’ll learn from my tribulations and make a set for your family, or at least enjoy a few laughs at my expense as you read along.

The Design

I chose to stick with the original tile size: 38mm high by 26.5mm wide. I could easily fit 6 rows of 13 tiles onto the bed of the Glowforge (about 280mm x 457mm working area), overflowing two rows of 13 and the two jokers onto a second piece, leaving a reasonable amount left over to recut any goofs. Measurements in hand, I set about creating the files in Inkscape. I eyeballed the radius for rounded corners and after looking at dozens and dozens of fonts went with … Arial Bold. Don’t judge.

The tiles are grouped into four colors, but in the original set each one just has the same circle under the number. I decided to represent each group with a symbol as well: circle, square, triangle and starburst (I can play endlessly with the corner count and spoke ratio of Inkscape’s “star and polygon” tool). Because I’m not a monster, I replaced the scary clown joker with a happy face (Wingdings character code 0x4A). Lastly, I added a Script MT Bold “N” for the back of the tiles. The “N” is for Nolan — I considered adding some form of our family crest but couldn’t find one I liked for the space. (New project: figure out how to draw a simple vector crest!)

For material, I used quarter-inch thick MDF board clad with cherry veneer on both sides. On my Glowforge Basic, I used 800 / 80 for engraving and 120 / Full for cutting. Feel free to use and alter these SVG files however you like:

• rummykub-clean-1.svg
• rummykub-clean-2.svg

Double-Sided Engraving

Engraving tiles on both sides presents an interesting challenge on the Glowforge; it’s tough to align designs precisely on a physical piece. Within a design, alignment is no problem — I can easily cut the tiles and center the numbers and shapes inside them. But getting the “N” engraved on the reverse side of already-cut pieces is a different story. The smaller the target piece, the harder it is to get exactly right; 106 individual tiles would be a nightmare!

This approach is the simplest and most effective I’ve found for the general alignment problem. But lucky for us, there is a super-cool trick that works for aligning front and back engravings for any shape that is symmetrical along its North-South axis — like our tiles! Details are in the link, but in brief it works like this:

1. Create your design with the elements for both sides aligned as desired. In the rummikub SVGs, every tile has an “N” stacked right on top of the number and shape. Choose different colors for the front and back elements so that Glowforge groups them into distinct engraving steps.
2. Fix the material to the Glowforge bed with tape or clips or whatever. This doesn’t have to be super-strong, but it should keep you from accidentally bumping the material once you’ve started. It’s really important that the material not move between steps!
3. Upload the design and configure settings for the cuts and front-side engravings. Set the back-side elements to “Ignore” and run the print.
4.  Open the lid, flip each cut piece to expose the back side, then place it back into its hole in the base material. It can be a bit tricky to pull the pieces out; I use a large hat pin to get a grip inside the cut.
5. Now configure the settings to engrave the elements on the back and ignore the others (including the cuts), and run the print again. Note that when you close the lid and the Glowforge rescans the bed, it may show the elements out of alignment. This is a lie! As long as you don’t move the physical material, your second print run will cut aligned with the first.
6. Tada! Perfect alignment on every tile.

Adding Color

Each tile “shape” has its own color. I chose red for the star, blue for the triangle, yellow for the square and green for the circle — plus black for the two jokers. I used this super-cool technique to apply color to the tiles neatly and absolutely love the result.

Pretty much everyone uses some kind of masking tape to cover their material and protect it from scorch marks that the laser can otherwise leave behind. When you buy “proofgrade” material direct from Glowforge it comes with a mask already in place; something like this item at Amazon does the trick for other stuff. It turns out that you can take advantage of this mask to fill in engravings with color as well.

With the masks still in place, I first cleaned ash and residue from each tile using baby wipes. This is a messy job and requires some care so that you don’t get the masks too wet; they need to stay adhered to the tiles for the next step. Then I just painted over the front side of each tile using acrylic paint from this set. Because the engraving is dark, it took a few coats to cover — four for most colors and five for the yellow. I let it dry for about ten minutes between coats, and then an hour before peeling off the masks. This was incredibly satisfying — the edges came away clean and crisp, and the color is bright and bold.

The last step was to cover the tiles on all sides with a few coats of clear enamel spray. The final result is a durable, nice looking set. Woo hoo!

Wait, this all seems fine?

“Seems” is the operative word here. The above is a textbook example of social media whitewashing — it’s all true, but skips over all of the not-so-pretty goofs and gotchas along the way. To wit:

Ghosts in the design

106 tiles, each with one cut and three engravings, is a lot of Glowforging and takes quite a bit of time (about two hours). The first hiccup came about two thirds of the way into this session as, seemingly at random, some of the engrave elements were just skipped. I couldn’t figure out a pattern to this so just wrote it off as “some bug,” maybe because of the large number of elements, and built new files to remake the ones that had been messed up.

Unfortunately, the “bug” kept showing up on some (not all) tiles every print, which was increasingly annoying as I quickly burned through my extra material trying to complete the set. Finally, as I was moving tiles around in the Glowforge interface for yet another run, I happened to notice that some of the engraving elements were showing up just a little darker than the others. WTF?

It turns out that, at some point during the dozens of copy/pastes involved in this design, I double-pasted some of the engraving elements — the elements that were showing up darker were actually two identical copies, one atop the other. And when a design has overlapping filled vector shapes, Glowforge just ignores the overlap area. I can’t find this documented anywhere, but it does show up in the community support forums with some regularity. Anyways, when I finally got the files fixed up, everything started working as intended.

Burn marks

A few of the tiles ended up with a weird pattern of burn marks along the edges on the back. I think there must have been something about the position of the tiles on the honeycomb tray that the material sits on in the Glowforge bed — some kind of reflection during the cutting process. It’s possible that I could have dialed down the power and still cut through the material without that side-effect. Anyways, while the aesthetics weren’t that horrible, part of the game is selecting tiles from a face-down draw pile. Unique patterns on the backs would be the equivalent of using a marked deck of cards … whoops! So I remade them.

Paint bleed under the mask

I actually expected this to be much more of a problem than it was. On a few of the pieces, the mask detached just a bit from the tile, causing the paint to bleed outside of the engraved area. I initially thought I might be able to scrape or sand off the extra, but that didn’t work very well — bits of the paint sort of smeared across the tile and it just looked bad. This only happened on a handful of tiles, so I just remade them instead of continuing to fight it.

Light and dark

The material I used has cherry veneer on both sides, but if you look closely one side is notably darker than the other (this was consistent across all the sheets of this stuff). I used light for the fronts, dark for the backs. Once I applied the masking tape, though, it was no longer clear which side was which. And after I got all the way through and was setting up to apply the enamel, I realized that I had flipped the sheet for a whole group of the tiles. And of course, the same thing about marked cards applies here — if you know that half of the green tiles appear lighter in the draw pile, it doesn’t make for a very fair game. I was just able to squeeze enough space out of my extra material to remake these too … whew.

Not the enamel too!

After this seemingly endless process of remaking and repainting problem tiles, I finally had a complete set. Home stretch! All that was left to do was to apply a few coats of clear enamel spray to protect the tiles during play. I’ve had trouble in the past with the enamel sticking the pieces to whatever they were sitting on (in this case a big piece of pressboard). My wife suggested that I put a penny under each tile to hold it just off the surface. A great idea, but because it was only 40° outside where I was painting, I was going to have to move the tiles inside to dry in a warmer environment — the pennies were just too slippery to stay in place during this move. Instead, I put little one-inch pieces of non-stick drawer liner under each one. Two coats on the fronts, wait for them to dry, flip them over, two coats on the backs, shuttling back and forth inside and outside, Bob’s your uncle.

Or not. Apparently tripling the dry time for the enamel (and touch-testing the tiles of course) was not sufficient. When I picked them up (thinking the project was completely finished, mind you) I discovered that the drawer liner was sticking to the tile fronts, leaving grey bits embedded in the enamel as they pulled away. Nooooooooooo! Through my tears of frustration, I used the flat side of a sharp knife to scrape off as much as I could — carefully touched up the paint where it had been damaged — and resprayed the fronts with two more coats of the enamel. The end result actually was fine — the scraping left notable marks at first, but the enamel coats fused together and left the final products looking ok.

Twist the knife

This last is just funny. As I was writing all of this up, I realized that the game wants tiles numbered 1-13 and I had created 1-14. Certainly better too many than too few, but come on.

I don’t remember any project where everything went exactly to plan. But this one takes the cake for sheer number of own-goals. Ah well … they will be fun to play with, and I will use both of those new techniques again for sure, and I can’t help but think of the old saw that a bad day fishing beats a good day working. Amen to that.