Walter and Destry are correct, I don't recall the name of the company who originally produced the Whiteline pad; but Pachmayer purchased the company (or rights to make the pad and use the Whiteline name), then changed to name to the "Pachmayer Whiteline" pad (I believe this took place in the early 50's). And I don't know what the policy may have been for recoil pads at Winchester; but in the 1940's Hunter Arms furnished and installed the original Whiteline pad on LC Smith shotguns (this was one of several pad options provided upon customer request by Hunter), and I suspect other makers may have had a similar policy. As to why a management decision was ever made to put a white line in a rubber pad, I have no idea; but suspect it had to do with marketing and brand recognition, an effort that was apparently very successful or Pachmayer would not have retained the whiteline feature for decades afterwards. I personally don't like the look; but the white line must have been a very appealing cosmetic feature in this era, as Marlin, Remington and many other makers copied that "look" for their hard-rubber butt plates and grip caps.
