OK, it's a complicated deal, but... veg tanning was the method for centuries to tan hides. Â The process took 6-9 months, then down to 1-2 months by the turn of the century (1905 I believe) when Freudenburg developed the process of adding chromium salts to the mix which had the principal effect of cutting the tanning time to 1-2 days. Â This obviously had great financial impact for Fruedenburg, but the product had some problems. Â First, there was no 'coverage', so only the best, non-marked hides could go thru the process. Â Second, there was no shrinkage, or grain tightening, so the leather ended up being very loose. Â In other words, the shoes made with this leather stretched too much. Â This is how 'Box Calf' came about; Freudenburg max stretched (boarded) the leather in two directions (opening the pores into a 'box'
before delivering to shoe manufacturers. Â This eliminated the stretching problem. Â Combine that with the fact that only flawless hides can go thru this process, and you have a very tough, clean leather. Â Now, since most hides are not flawless, a tannery who wants to speed up the processing time (most tanneries) can take a lower grade hide, chrome tan it and follow with a veg 'retan' which has the effect of shrinking out (6-8% total) minor defects such as fat wrinkles. Â This also provides a medium for the dye to provide a more uniform coverage, which also covers up imperfections. Â This is why you see a 'waxy' film in the reflection as well as a uniform finish - it flows well after the re-tan. Â So, this is the most authentic definition of 'corrected grain'. Â Now, of course, most associate the rolled on, built up (or worse, sprayed on) pigment process as 'corrected grain'. Â To finish, this leather we see is 'corrected grain', but better than the covered 'corrected grain' we see more of. sorry about the goofy winking guy, don't know how I did that.