You guys do check your ref or the movie, right?
Barbossa's coat is odd indeed, but those black "holes" are actually nubs of black thread I believe.
Check the ref below...
View attachment 598004
View attachment 598005
Notice how the sunlight is catching on the raised stitching. The material (not leather) is also very dimpled.
I know this is likely impossible to recreate and we may have to accept "holes" for the look, but just want to make the material as close as we can.
Neoprene, 'Nike' style mesh and pleather with holes is not going to look right.