Hey, MRSB! Glad you joined the forum with a post. Welcome! I can't answer your question, as I've never used those supplies, but if anyone here knows, they will for sure answer you. This is a great group of people, and very helpful. We'd love to see some of your work. Post a photo or two soon, ok? It'd be fun to see what you're up to.

Hi, I've never tried painting grout befor, but maybe if you tried using gesso or another primer on the grout befor painting it may help. good luck. I'll bet the shimmery color is pretty.

I always use the cheap acrylic paints and they work great. I never water them down though. They make the piece
seem really finished and sealed looking. I paint it on thick, and give it a couple minutes, and wipe the glass.
Never had a problem!..sorry to hear that isn't working for you! You might need to put it on a little more heavy, and let it soak in. I do mine about an hour or so after a project, don't know if that matters. Are you using sanded grout? That might be the problem? Sanded works great with
paints!

Thank you thank you thank you! I think I am using non-sanded grout. Yikes! I'll try using full strenth acrylic with sanded grout. And I'll post a picture of a before and after! Thanks again.

Hi and welcome. I think your problem has already been identified - I do not like unsanded grout at all. I paint all my grout (sanded grout) using acrylic paints (the brand I happen to use is Ceramcoat by Delta) and I do not have a problem. The method of application that works best for me is to sponge on the paint using natural sea sponges. Somehow that works better than a brush. I squirt the paint into a jar lid, dip in the dampened sponge, dab all over the mosaic piece, wait until the paint is almost dry, then scrub the tesserae with a damp terrycloth rag. Hope this helps!

I use white sand grout and add my paint right to the grout. I mix the grout first then add the color i want to the grout. It works great.

Hi, I'm new to this group and mosaics also. I read in one
of my books: to mix the acrylic paint with the grout,sounds
like that makes it a little easier than painting it on.
Good luck from one beginner to another beginner.