How much does leather typically stretch when wet vs when dry?

Answer 1

Most leather, when dry, tends to rip or tear the fibers and usually will not stretch except over a long period of time of with great force.

To stretch leather, it is usually treated, not with water, but with a liquid shoe stretcher fluid to relax the leather fibers and allow stretching, without tearing.

When dry, leather might stretch about 1/2 to 1 percent if one is careful. Using professional stretcher fluid, typical leather goods can be stretched between 5 and 10 percent, depending upon the type of leather and the direction of the fiber "grain."

Old techniques (pioneer days) using water as the stretching fluid could yield about a 2 to 5 percent increase, but also tended to damage the leather.

Answer 2

Can Leather Stretch

Answer 3

depends what kind of leather, but it will stretch more when wet than when dry