Back to Dye Printing Tricks & Tips
They can be very similar--but react very differently. Take a blue crayon. Color a star on a piece of paper at regular pressure. You get the true 100% level of that color. Fill in another circle at only half the pressure. You'd get about a 50% tint of that same color.
The transparency affect is more like tissue paper. The less opaque the paper, the more of something else you can see through it. But the color of the tissue paper does interact with the color of whatever is underneath.
Tint:
Here's two shapes. A 100% dark blue star on a yellow box with a black stroke.
Say we tint the blue star to 50%. It's now half as light, but still opaque. No part of the box shows through.
To image this graphic the computer would have to create three plates. One for the star. One for the yellow fill of the box. And one for the black stroke outline. Notice how each does not overlap?
Transparency:
Here we have two stars. One is a 50% tint of the blue. The lower one is a 50% transparency. No difference, right?
Ah, only because the "white paper" isn't giving away the transparent affects.
Let's get rid of the 50% tinted star and replace it with the 50% transparent star.
Now we see the blue and the yellow mix to make a sickly green. The black is also mixing with the blue, but overrides it completely (to the eye, but not to the computer).
So for the transparency to work at the imaging stage no longer are there three elements (the star, the box, and the stroke) but now five elements:
The 50% transparent blue shape (truncated star)
The 50% transparent blue and 100% yellow star piece.
The 100% yellow fill with a bite out of it.
The 100% black stroke of the box.
The 100% black stroke plus the 50% blue overlapping it.
Now let's show what the outcome of a transparency on a transparency.
50% plus a 50% gets us back to 100% (zero transparency),
so the overlap outside the yellow box gets us back to the solid blue. The
sickly greens overlap to make a forest green.
The stars are now 30%. The overlap is 60% (on the white and yellow). Some people have a hard time with transparencies on transparencies affecting one another, not just the background. Plan for this "overlapping" build up.
If you want the stars to be the same "color" and transparent, make them a unit BEFORE making them transparent. Otherwise you're adding more pixels/ink and therefore getting less transparent.
Be Careful
Depending on your application, this action will be successful (InDesign CS2 and above, Illustrator CS and above, Freehand 10 and above) or a disaster.
Remember that what you see on the screen may or may not be printable depending on how the job is set up.
Some applications turn spot colors to process as soon as you apply a transparency effect (like blends, gradients, drop shadows as well as simple translucency). A two color job suddenly becomes a six color job (the two spot colors you think you set up for plus the four process colors needed to "mix" the transparency effect).
Be aware that the limitations of ink on paper are completely different than what a computer monitor can display.
The above graphic is a hideously simple example. Just think of the number of pixels necessary to add a drop shadow to a complicated background, or to merge a face into a sunset sky. Early InDesign drop shadows looked fine on screen, but if you used it on a text frame the actual outline of the frame also had a shadow! It didn't show up on screen, only lightly on some deskjets but very noticeably at the RIP!
