4 to 5 oz leather weight is good. A soft pigskin lining is good. Pockets to slide the bible cover into are a necessity. They should be lined with pigskin also. But you need to add a spacer along the outside of the pockets the same thickness as the bible cover. Use a paper book cover if you want but the spacer will relieve any binding that might occur. It only needs to be 1/4" wide around the pockets. I add it all the way around so there is a good binding to sew in a zipper if whoever the cover is for wants one. 1/4" is also wide enough to lace the edge of the cover which looks much better than sewing it. A double lace is ok but I prefer a triple lace. It looks better. Also when gluing the lining into the cover, it's a good idea to glue it in with the cover semi folded so there are no wrinkles to dig into the bible when it is closed.
