Calibrating a Black and White image

[YooDooRight]

Im calibrating a black and white image for the cover of a cd case to be printed on uncoated card and understand (correctly?) that i need to leave a buffer zone each end of my k percentages to avoid dissapearing dots, about 10-15% for uncoated stock.

So in practice this means my tiff image has no k values more than 90% or less than 10%, so at print will my highlights and shadows naturally brighten and darken slightly through dot gain corrrecting the images contrast? On screen the image lacks a little punch in these highlights and shadow areas as no dot is darker than 90% or lighter than 10%... are these areas going to fill in slightly and give me a punchier image?

Also, if im embedding a colour profile that already allows for 10% dot gain, am i repeating myself?

Thanks

YDR

[Broacher]

I don't embed profiles in greyscales. These used to cause real problems in many RIPs and apps but mostly I don't embed because of the same reason I don't embed profiles in CMYK. Too many Santas, not enough elves. Embedded profiling is sometimes a necessity (an all RGB workflow, for example), but more oft than not, I've found it just an invitation for more monkeywrenches and religious conversion.

OTOH, many prepress workflows now automatically apply dotgain profile corrections to submitted images. I've had that blow up on me too! The solution, when you can, is to ask the printer for advice on this. That isn't always possible, so yes--there's still chances of error and trial, but there's always... more prayer!

The mid-grey gain is one thing, but it's the endpoints where all the shadow/highlight detail problems can emerge. If you know that the printer can only hold a minimum 5% screen, or a max of 93% before solid fill-in in the shadows, then you want to pull your output range into this range to help balance the dynamic tone loss. Tip: always do this after your final sharpening tweak.

Where this is most obvious is newsprint production where the dot gains are also the highest. There's also a safety 'blow-out' on the top-top highlight adjustment you can make if you have specular highlight detail you want to keep-- and/or avoid flesh highlight 'psoriasis'.

Again, it all depends on what and who is done to your file between handoff and the ink hitting the paper. Ask, ask, and ask again. You want to be polite but thorough enough so they give you the best quality control, without kicking you off their free Christmas calendar list.

[pmkcreations]

The printer should have their equipment calibrated to compensate for the press gain. If they don't it's their responsibility to match what you want to see.
In most cases, get color where you want. Get a proof from the printer and make sure that they match it on press if you like the proof. That is how it should work.
Now if your photo is really light or muddy, then that is a different case.