I made these on my laser cutter a few years ago. The lids use magnets to help them stay on. They’re cut from 1/8" maple and walnut plywoods. Short demo video here: https://www.youtube.com/watch?v=UjAaykdz8H8. If you have access to a laser cutter and are interested in making some yourself, the files are available for download on my website: https://www.laseredby.me/shop/iroshizuku-ink-box
edit: sorry - when I added the picture it lost the gallery link. https://imgur.com/gallery/xRRRxev
Oh also worth mentioning for anyone who makes their own version - of the 8 that I made, 1 of the bottles was a little tight in the cutout. I think i used some sandpaper to loosen it up enough to not be bothersome. But if you’re concerned about it you might want to increase the size of the cutout a little bit and/or cut a sample piece to check the fit.