To follow-up on Jeremiah’s excellent comment there is the aniline dye used on all the leather [drum dyed] and then a very small amount of protective pigment finish would be used (aka semi-aniline) all the way up to a lot of pigment finish could be used (aka pigment finished). More pigment would be needed to ensure a uniform color on poor quality leather, so I would expect jackets to be mostly semi-aniline as made (very little pigment finish on fresh unused leather) while used refinished ones would always be consider pigment finished with more pigment required to cover damage/scars/spots/etc. from use. So I think my horsehide semi-aniline Eastman 33-1729 is spot on.
Edit - From the horsehide spec the quality requirement was “uniform color free from obvious imperfections, ie, holes, scratches, cockle or poor grain” while from the cowhide spec “holes, healed grain scratches, scars, small brands and grub holes are permissible”. So most likely semi-aniline for high quality horsehide, but cowhide may go from semi-aniline to a heavier pigment finish depending upon the varying leather quality. A damaged/used refurbished jacket would always be with the heavier "pigment" finish, yes?