As a former journeyman printer, I can help you with the particulars on these cards. The "blue lines" that you see on the first print Gretzky rookies are nothing mor than scratches on the cyan printing plate. In the 3 color process printing methods, negative images are burned to the metal printing plates (there are 4 plates used to make a process photo black, cyan, magenta, and yellow) Ink will only stick to an image burned on the plates (the ink also sticks to scratches on the plates), and the rest is washed away by a special water/chemical solution during the printing run. The reason why the blue marks are not on the 2nd printings is simple: they changed the printing plates and used new ones that weren't scratched for the 2nd run.
The card you show with the blue showing is just a register, or registration issue. When the card runs through all the 4 colors of ink, they must line up perfectly to form a crisp, clear process picture. The colors can be moved frontwards, or backwards (circumference), and left to right (sidelay)to allign these colors to form the process picture. In this case the blue is not alligned properly with the other colors. Usually they are chucked out, but I guess quality control was not an issue back in the day. :| When the colors are not alligned perfectly, the picture will appear blurry. That's your printing 101 lesson for today. Stay tuned tomorrow for plate burning 101, to be followed by plate registration on Friday! :dance:
