The Grouting Step That Scares Every Beginner — And How to Nail It

By the time you're ready to grout, you have hours of time — and possibly a decent amount of money — invested in your piece. So it makes sense that grouting feels terrifying — you're about to smother the whole thing in dark goo.

I compare it to going around the dark side of the moon. You lose contact with ground control, and everyone just hopes it comes out okay on the other side.

Here's the good news: you don't have to guess.

Test before you commit The dry grout test is exactly what it sounds like. Once your adhesive is completely dry — at least 24 hours after the last piece goes down — scoop a spoonful of dry grout onto your piece and work it into the gaps. Wipe it off the glass as best you can. It sounds funny, but dry grout is the color the grout will dry back to. You're getting a real preview, no water required.

You can test multiple colors at the same time in different areas of the piece and compare them side by side. Once you've decided that charcoal was the right choice and your instructor isn't crazy — tip the piece over and dump the grout in the trash.

NOT the sink. (Ask me how I know.)

Don't own the color you want to test? That's where digital tools help. The Groutr app (iOS and Android) lets you upload a photo of your piece and virtually preview different grout colors before you buy them — genuinely useful when you're standing in the store deciding between charcoal and slate. Groutr is a woman-owned, artist-owned small business that keeps getting better, so check back regularly. Canva's AI tools can do something similar if you're already working there.

Still not certain? Start light.

If you've tested and you're still not sure, go with the lighter color. Because here's the safety net nobody tells you about: you can regrout. Just apply the darker grout right over the lighter one. It's that simple.

One of my students chose "rolling fog" — a soft, pretty gray — thinking it would look beautiful with her pink glass. I get the urge completely. It's soft and feminine. But take a look at what she found when she regrouted with charcoal:

The glass is supposed to be the star. Dark grout — charcoal especially — makes every piece pop in a way that lighter colors just don't. It's counter-intuitive, but those photos don't lie.

The payoff

Grouting is the step that transforms your piece from a collection of glass into something finished and whole. Test your color, trust the process, and breathe.

You've got this. And if you want to see the full grouting process from start to finish, the video is right here: hendersonartsllc.com/grouting-video