[con40]

These two cards show a great example how ink density can affect a card's overall color.

The card on the left has much more cyan ink (light blue) applied than the card on the right. The result is that any colors with a percentage of cyan ink get darker and bolder in value as the ink density increases.

One of the pressman's main jobs is to maintain consistent ink levels on press. There are four inks (cyan, magenta, yellow and black) on a standard full-color print job. These four inks in various combinations print all the colors we see in any printed matter of the 1920s up through today. Keeping the right densities of ink is like a balancing act. When the levels shift too much, the proportions of ink get out of balance and the image changes... sometimes dramatically.

If SCD or any other reptatble source started considering these ink shifts actual variations, then EVERY card ever printed would have multiple variations extant.