I'm working on a project where I want to add a gradient over the bottom of a picture so it fades to the background. However, when I save the file to PDF, the gradient gets a grey color, not the black I selected. When I save as PNG, it doesn't change the color.
Should I change something in my settings somewhere? I've tried different PDF-viewers, but every viewer shows the same weird grey color.
Also, while we're at it, why does the gradient desaturate the image?
Examples
Illustrator
PNG
You most probably used a 'poor' black as the black in the gradient: 100% black ink, but no C, M or Y.
The K ink is not black by any means: it's dark grey at best, and doesn't stand scrutiny when printed on a large area. To get a good, saturated black, you'd better use a 'rich' black: 100%K with some percentages of other inks added. You can influence the 'character' of the black with these colours: the added colours shine through the black, giving a very cold black with 100%C, 100%K, or a warm and red black with 60%C 40%M 100%K. Be sure not to exceed the maximum ink percentage of ~280%.
To use a 'rich' black in a work, it's best to make it a swatch, so you use the same black all the time. Makes it easier to include it in a gradient, too.
Do not use a rich black for text. Alignment between printing plates is always imperfect, yielding colour sheens at the borders of the letterforms, severely hindering legibility. to say nothing of sharpness.
.pdf preset for you to download.
– Vincent
Nov 4 '14 at 13:32
