I have an OLD wooden board ( 14" x 54" ) that has a slight warp ... whats a good pad/cover to get ?? Is the one with the grid a good one ?? Thickness matter ??

I covered a piece of study plywood with thick foil tape, then a wool blanket, then a sturdy piece of linen. Staple all pieces on the back.

Remember not to have the pad too thick. You want to IRON the fabric not press it into the pad.

Good luck

I agree that you don't want thick padding. You will iron folds in your carefully prepared 1/4" seams if it's too thick

i would turn it upside down on 1/4" or 1/2" ply, trace around and then just lay that pc on top. it does not have to be attached but it will cure the warp. Now wrap with the thickness you prefer...blanket from thrift store is good if you don't have one of your own. 3 or 4 layers of old blanket...just keep it firm like everyone said...then cover with whatever you like...i like 1" gingham so i have the straight lines and diagonals.... you could even mark a couple of diagonals with permanent marker or a sewn stitch line (which i would prefer just in case the marker came off with steam)... then make sure you pull from the center to the outside corners when stapling on... to keep it straight...just staple in the middle, move to the next section, staple in the middle again (go back and forth on opposite sides so you can keep it straight. the reason i suggest that you use gingham for the squares is that the pre-marked covers will be too big for the old wooden boards....personally, i like gingham or new denim. the denim cover i have is absorbent, thick, all cotton....and has lasted for many years. the gingham is my preference for square ups.....