Huh? What kind of 3M tape???
Thanks.
Usually, when people reference 3M tape for gun grips they're talking about 3M's anti-skid tape. You can generally find it in hardware stores in prepackaged rolls or (in old-fashioned mom and pop shops) huge rolls which are cut off at on-demand lengths.
They have two varieties. The black stuff is sort of like a coarse sandpaper or skateboard tape. The gray stuff (usually harder to find) is more rubbery -- a little closer to Hogue grips in tape form.
Another option is Pac-Skin in roll form. It's like the Pachmayr grips in sheet form. Most of the gun-type internet big box stores (Midway, Natchez, etc.) carry it.
The gray 3M or Pachmayr stuff are a little easier on your hands, especially if you're not regularly doing manual labor to toughen them.