Johanan; Thanks for the filip on your DIY non-slip!
I was really mostly just curious as to how you did yours - I have tried dilute PVA ("meh" and tends to not adhere all that well to the styrene (but super-cleaning the styrene does help), Future (actually adheres fairly well, but does tend to self-level and run off to places you don't want grit to stick on, so requires careful management, in my experience), wet paint, and eventually ended up going with "Stynylrez" model primer. The latter paint adheres well to styrene, resin, and PE as it's a purpose-made primer for those materials, and it can be easily and accurately brushed on to control where you actually get grit to adhere. My test-bed was the Takom Merk 2b... A build with lots of detail embedded in the non-slip application!
I'm not sure what that "hamster litter" is - the grit size looks pretty good on your build, but I can't help but think that that fine a grit would make for dirty and sandy hamsters!
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When I kept hamsters, perhaps 60 years ago, I always used cedar shavings and such, or newspaper shreds, for mine... They clearly loved burrowing into and kicking that stuff around, and nobody wants a bored hamster, right!? I seriously doubt that my old-school hamster bedding would make a nice application on any model!
My grit choice is fine tile grout that I actually collect from the floor in the cement and grout products isle of my local Big Box Home Center store! For application, I sift it onto the wet primer patches through a little straw - enables precise locating when applying and limits the surplus that one gets.
In about every way, it actually comes out pretty much like what you have done. And it's likewise easy to remove and to add more onto, as one desires.
Again, always curious as to how DIY folks do this - the VMS kit sounds fine, but it's just an expensive way to do what you, I, and others get done for cheap!
Looking forward to seeing paint on it!
Cheers! Bob