TAC calculator (total area coverage)
Add up total area coverage across your separations, and understand why a single universal limit does not exist.
Total area coverage, or TAC, is the sum of all ink percentages in the heaviest area of an image. It matters because too much ink in one place causes set off, poor drying, picking, register problems and trapping failures.
The sum itself is simple addition. The judgement is knowing what limit applies to your process and substrate, and that number is not universal.
Calculator
How to use it
- Enter Cyan in %
- Enter Magenta in %
- Enter Yellow in %
- Enter Black in %
- Enter Extra separation 1 in %. Orange, green, violet or a spot colour, if present
- Enter Extra separation 2 in %
- Enter Your agreed limit in %. Optional. From your profile or customer specification.
Formula
Worked example
A rich black built as C70 M60 Y50 K80 gives a TAC of 260%. Whether that is acceptable depends entirely on where it is printing. On a coated sheet offset job it is unremarkable. On an uncoated stock, on newsprint, or in a fast drying flexible packaging structure it may be well beyond what the process will hold.
Assumptions
- The calculator adds the percentages you enter for the single heaviest area of the image. It does not inspect a file.
- Extended gamut separations are added on the same basis as process colours, which is how most specifications treat them.
Limitations
Every calculator on this site gives a planning figure, not a production guarantee. Check the result against your own records before committing material or money to it.
- There is no universal safe TAC. It depends on process, substrate, ink chemistry, drying or curing, press speed and the ICC profile in use.
- A file can pass a TAC check and still cause trouble if the heavy area is large, in a difficult position, or in a trap.
- This tool does not analyse a PDF. For production work use your prepress software to find the true maximum across the whole file.
Common mistakes
- Applying an offset TAC limit to flexible packaging, or a coated limit to uncoated stock.
- Checking only the rich black and missing a heavier area elsewhere in an image.
- Reducing TAC by pulling back black alone, which usually costs shadow detail. Proper separation settings or a profile rebuild is the better route.
Frequently asked questions
What is TAC in printing?
Total area coverage is the sum of all ink percentages in the heaviest part of an image. A patch of C70 M60 Y50 K80 has a TAC of 260%. It is a measure of how much ink is being asked to sit in one place.
What is a good TAC limit?
There is no single answer, which is why this calculator does not give a pass or fail. The limit comes from your process, substrate, ink and drying, and it should be set in your ICC profile or agreed in the customer specification.
Does extended gamut printing change TAC?
Yes. Additional separations such as orange, green and violet add to total coverage, so an extended gamut job can reach a high TAC even when no single channel is heavy.
How do I reduce TAC without losing shadow detail?
Adjust the separation settings when building or rebuilding the profile, using GCR or UCR to move colour out of the three chromatic channels and into black, rather than simply reducing the black channel afterwards.