I type in three languages (English, Russian, and Hebrew) pretty regularly, and, unfortunately, I am not that great at touch typing, especially in Hebrew. Which means I need language stickers for my keyboards (at least the ones that I use often).
My journey to find a set of stickers to accommodate all these combinations had some limited luck. There are a few trilingual keyboard stickers out there, but they are not perfect: the colors and the fonts are not what I wanted.
Of course, I could have custom ordered a combo that worked for me (and I did that a couple of times), but it's was not a super quick or a cheap process, and if there was something I wanted to change after you having finally seen the stickers in person, I was out of luck unless I wanted to pay for a MOQ again and wait for stickers to ship.
Another thing to consider is that most language stickers are designed for the top surface of the keys. This has several disadvantages:
1. The same set of stickers may not look well with every keycap set, depending on color, font of existing legends, and profile. If you have spherical keycaps, good luck finding a set of stickers that will properly adhere and stay on top, and if you have a black IBM M13, standard sticker sizes tend to be too wide for its keys. If you have a vintage Alps set with those dots in the middle of F and J keys, most stickers will not adhere well around them, unless you pay for a stickers with non-standard cutouts.
2. Over time, finger oils, dirt, and grime accumulate around the stickers' edges. It looks very unsightly, and if you try to clean that grime, it's easy to accidentally damage or peel the edges.
3. Top keycap surface has some roughness, so no matter how carefully you apply the stickers and how much pressure you apply, adhesion will not be perfect and there will be some micro-bubbles between the vinyl and the keycap's surface. Stickers will stay on, but will likely not look perfect unless the keycaps are of very light color or you are using opaque stickers with background color perfectly matching the color of the keycap.
So I tried making my own stickers for front surface of the keycaps, similar to front printing. After wasting a ton of paper, film, vinyl, laminate, toner, and time on trying to cut out each tiny sticker individually, I finally gave up and bought myself a vinyl cutter, specifically Brother ScanNCut SDX85, which is their beginner model. These cutters aren't as ubiquitous as Cricut or Silouette, there is less info on them online, and they have a few other quirks, but they also have a few big advantages for this specific application. The biggest one for me is the built-in scanner, which makes it much easier to make cutouts in the correct places on the pre-printed vinyl sheets.
So here is the process I followed:
1. Create a sheet with your sublegends using whatever colors, fonts, etc. you desire. I don't have a dedicated vector graphics software, so I just use PowerPoint, which works well enough for me (I tried Word first, but found its drawing tools much more frustrating to use). If you are using a laser printer (in my case, HP Color LaserJet Pro M479fdw) and you want to create opaque stickers with black background, you may want to tinker with black color for it to look good on vinyl: I adjusted it to (8,8,8) instead of (0,0,0) in the RGB space, for example. I think this makes the printer use a combination of color toners instead of black, which makes for a darker, more saturated black color.
2. Print your sticker sheet on a glossy sticker film/vinyl that's appropriate for your printer type (some materials designed for inkjet printers will melt inside a laser printer and will mess it up). I used these sheets for transparent stickers and these ones for opaque stickers.
3. Apply a self-adhesive laminating sheet using this or similar technique. Unfortunately, gloss laminating sheets do not look great on keyboard stickers; the selection of matte self-laminating sheets is more limited, and the ones I have been using so far are a pain to apply. This scraper and roller kit has been very helpful.
4. Scan the printed sheet into your ScanNCut machine - make sure you are using a low-tack mat, otherwise the pack of sticker paper will stick to your mat surface and will be pretty much impossible to remove - you'll end up ruining the sticker sheet and the mat.
5. Import the image into CanvasWorks software (I use wifi but you can use a USB stick or a direct-to-computer USB cable connection). Create rectangular cuts with rounded corners wherever you need, and then export the FCM file back to your cutting machine.
6. Import the FCM file into your machine, and make the cuts using appropriate settings; enable "half-cut" option so the cutter cuts through laminate and vinyl but leaves the backing sheet intact. You may need to experiment with correct settings and blade type for your specific combo of vinyl and laminate, so prepare to waste a few sheets in the process.
You now have a set of stickers that you can carefully peel and apply (I recommend using medical gloves) to your keycaps. For black stickers, consider using a permanent marker around the edges and then wiping excess marker ink with alcohol wipes - this will make the sticker edges not stand out as much.
Time will tell if they will hold up as well as the professionally made ones - I will probably have to experiment some more with different materials and cutter settings.