First, sorry for requesting a quick response...I Live out of town and we need to get this done before I leave.
Second, my sister in law and installed her glass and stone tile blend backsplash two days ago. We are ready to grout, but I'm not sure if I can go with sanded grout. The tile is the standard 12x12 sheets, so the spacing is 1/8inch. I prefer sanded, but I've read customers complaining that the grout filled in the porus spots on the stone. When I installed my own tumbled marble backsplash this past summer...I liked the grout filling in some of the spots. Is that not good on these blended sheets with glass? Any helpful hints would be greatly appreciated.
You can use either one at 1/8". Personal preference whether you want the grout to fill in the holes in the stone or not. If it is a highly pocked stone like travertine et al, and the backsplash is in a kitchen, or bathroom where it's likely to get splashed with gunk, I highly recommend filling in the holes (or use a stone that doesn't have holes.) If the backsplash is more for looks, then the holes are fine.
Actually I'm not sure what you're asking. Whether you use sanded or not does not affect whether the grout will fill in the porous spots.
Sanded grout can sometimes scratch glass, but you'll probably be OK.