Question 1

Is a hard backer required to use this product? I would be worried about applying uneven pressure through my fingers.

Accepted Answer

it is flexible so you would need a block for hard flat sanding

Question 2

Are the 320-400 grit 320 on one side and 400 on the other? How are we supposed to tell them apart if you don't lable them?

Accepted Answer

The 320-400 grade refers to the grinding fineness in the range of 320-400 grade.

Question 3

When the description says 320-400 grit, does that mean one side is 320 and the other side is 400?

Accepted Answer

I think both sides are the same grit

BokWin 16Pcs Sanding Sponge, 120 Grit Washable Sponge Sand Blocks, Wet and Dry Sanding Blocks for Plastic, Wood, Metal, Furniture (Fine Grade)