>>I have read that I need to make the large coloured areas on my pages in Photoshop rather than in Quark, using a little noise, in order to avoid banding on final output.<<

Only if it's a gradient tone. Flat tints and solids are not effected. And only if the gradient tone is quite large, involving one or possibly just two colours. Well, actually, there's a formula for predicting banding but the thing to remember is to not stretch between two tints too much and that the more ink channels involved, the less likely it's going to show. Adobe has something called 'smooth shading' built into its apps which helps minimize banding by telling the RIP to kick the 8 bit tones up to 11 bits while calculating out the best raster representation in memory after it's been 'processed' for this.

Here's a basic math example with one colour to demonstrate the banding threshold:

Let's say you have a ten inch rectangle with a zero to 100 percent gradient. The maximum steps in postscript tints is 256. That means you're spreading 256 steps over ten inches, or-- 25.6 steps per inch. But if you made the same sized gradient going from a 50% tint to 0 then you'd be doubling the width of the step to 1/13 if an inch, which would be visible. Generally speaking, any band greater than 1/16' is visible. So let's say you can have a maximum of 20 steps per inch. Therefore, the maximum postscript length of a one colour gradient that could be made without banding would be: 256/20, or 12.8 inches. But remember, that's a full 0-100 gradient. Also, you have to be aware of the resolution of both your linescreen settings, and PPI of your output device. The higher the linescreen, the lower the number of steps available-- banding likeliehood increases. The lower the PPI available at output the fewer total possible tone steps as well, and banding liekliehood increases.

Cheers Broacher for a speedy and informative reply, probably just saved me hours of work. There are so many do's and don'ts to this game aren't there.

>>There are so many do's and don'ts to this game aren't there.<<

Hmm... the don'ts always seem to outnumber the do's. But if you stick to it, the don'ts become kinda transparent. Like learning to drive through a big city-- you get to know what routes to avoid, where there's potholes, construction delays. And the technology is always improving to make the don'ts less and less and the drive safer.

I mean, when I think about what it used to take to say, do something as basic now as create a decent drop shadow or bevel in Photoshop 3, or output to a RIP from Windows 2... yi. And if their weren't as many 'do's and don'ts' in this game, why-- anyone might think they could simply put the car on auto-designer and... uh-oh. Wait a sec....

People sometimes mention 'paying your dues'. Maybe it should be 'paying your don'ts'.