This is an addendum to the email just sent out. Many of you will no-doubt email back saying to me that my previous email is not the exact definition of BPC!  You are correct. The exact definition is that BPC corrects for differences in black between one device (say a monitor) and another device (say a printer printing on Matte paper) that doesn’t have the same black DEPTH (or darkness). However, the original personal definition still holds as the ultimate original purpose of BPC was to correct for lack of shadow detail when printing from a monitor to (in particular) paper that is not able to replicate the same black depth. The physical reasons for that are how the black ink gets into the paper.