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What does gang run mean?
It means laying out different jobs, often for different customers, side by side on the same sheet and printing them together. After printing, each job is cut out into its own stack.
It is most common for small, short-run work: business cards, brochures, flyers, labels and postcards. Some printers make a regular service of it, collecting jobs for one stock and colour set during the day and printing once the sheet is full.
Where does the saving come from?
In offset printing every job needs its own plate set and make-ready. Five small four-colour jobs printed separately need five plate sets (twenty plates) and five make-readies. Ganged onto one sheet, they need one set and one make-ready.
Paper is a different story: there is often no saving there. Printed separately, the jobs may use the same number of sheets or fewer, and if the run lengths are unbalanced a gang run can even waste paper. So the question “what if we ran them separately?” has to be asked for plates, make-ready and paper one by one.
Which jobs can share a sheet?
Everything on the sheet is printed under the same conditions, so ganged jobs need to share:
- The same stock and weight.
- The same colours: 4/4, 4/0 and so on. A double-sided job does not gang with a single-sided one.
- The same finishing: lamination, varnish, scoring. A matt-laminated job and an unlaminated one do not go on the same sheet.
- Similar deadlines: if one file is late, everyone on the sheet waits.
- Colour tolerance: if the ink is adjusted to hit one customer's brand colour exactly, the jobs beside it shift too. Colour-critical work is better printed on its own.
Different run lengths: how to split the cells
The number of cells (positions) on the sheet is shared in proportion to each job's run length, so that all jobs finish on the same number of sheets. Example: the sheet has 20 cells; job A needs 1,000, job B needs 4,000.
Give A 4 cells and B 16 and both finish in 250 sheets (1,000 ÷ 4 = 250, 4,000 ÷ 16 = 250). Split them 10 and 10 and you would need 400 sheets for B, with 3,000 extra copies of A — paper that goes straight to waste.
The ratios rarely come out exact. Then you pick the nearest split and accept the overrun knowingly. Do not forget waste: print and cutting spoilage is added on top of the sheet count.
Gutters between jobs and the cutting order
Copies of the same job can share a cut with no gap. Different jobs, though, would bleed into each other's edges, so a gutter of about twice the bleed is usually left between them: 6 mm for jobs with 3 mm bleed.
Plan the cutting from the start. On the guillotine the sheet is first cut into horizontal strips, then the strips into pieces. Lay the jobs out along those strips and the cutting is quick; a sheet with jobs scattered across the strips can take hours at the cutter.
Splitting the price between customers
Plates and make-ready are shared by the jobs on the sheet. The simplest way is by area: a job that takes 20% of the sheet pays 20% of the shared cost. Paper and impressions are split the same way; finishing such as cutting and packing is charged per job.