I spent the morning printing the second color on a lithograph. As I was working, I was struck by how much you have to be paying attention to the subtle details to get things to print consistently and well.
The first thing that I noticed was that I was rolling too fast. Color ink is always all over the place in terms of consistency. This particular batch was pretty tacky, so I had added some mag to cut the tack and stiffen it up. As I rolled at my usual brisk pace, I noticed that the image was not accepting ink quite as well as I would like. It was taking a lot of passes and not being real consistent as to how many. I could have tweaked the ink again (I may have over done it a bit with the mag, but I tend to like a little stiffer ink), but I found that by slowing the roll down (both on the slab and on the stone) it gave the ink just a little longer to make the connection. I discovered that I could hear the image take the ink. First pass, no sound. Second pass, a faint whisper. Third pass, a little stronger ‘sizzle’ and so on. Just with that change, the image began to roll up well and consistently.
After a couple of impressions, I noticed that the registration mark on the trailing end of the stone was very slightly off. With T-bar registration, there is always a tiny bit of variation as there is not a precise mechanical positioning of the paper. In this case, however, things were just a tiny bit off in a consistent fashion. Adjusting were I placed the tail edge of the paper relative to the mark solved the problem and everything printed more consistently. The adjustment was about the width of the pencil mark. Small, but noticeable.
It is the same with every process. Careful observation and attention to the little details are the keys to a consistent edition.