Offset or Digital for a Five-Thousand Leaflet Order
A Bhubaneswar shop must quote for 5,000 A5 leaflets, four colours on both sides, on 130 gsm art paper, delivery in five working days. It owns a two-colour offset press and a digital toner press. For offset, the estimator assumes eight plates at ₹350 each, four make-ready passes of 200 sheets each, labour of ₹1,000 per pass, ink ₹1,200, and paper at ₹70 per kg; an A4 sheet carries two A5 leaflets, and 130 gsm A4 paper weighs about 8.1 g. For digital, the click charge is ₹2.50 per A4 side, paper is the same, and setup is ₹500. The offset press is free, but the regular operator is on leave for the first two days, so only a trainee can run it; the digital press can be supervised by the owner. The customer will pay a 10% premium for delivery in three days but will reject any job with visible toner gloss difference or offset set-off. Waste allowance is 5%.
1. Calculate the estimated production cost per leaflet for offset and for digital, showing your workings. On cost alone, which process is cheaper?
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Net paper: 5,000 A5 leaflets ÷ 2 per A4 sheet = 2,500 A4 sheets. 2,500 × 8.1 g = 20,250 g = 20.25 kg.
Offset paper: add make-ready 4 passes × 200 sheets = 800 sheets = 6.48 kg. Total before waste = 26.73 kg. Add 5% waste = 28.07 kg. Paper cost = 28.07 × ₹70 = ₹1,965.
Offset other costs: plates 8 × ₹350 = ₹2,800; make-ready labour 4 × ₹1,000 = ₹4,000; ink ₹1,200. Total = ₹1,965 + ₹2,800 + ₹4,000 + ₹1,200 = ₹9,965. Per leaflet = ₹9,965 ÷ 5,000 = ₹1.99.
Digital paper: 2,500 sheets × 8.1 g = 20.25 kg; add 5% waste = 21.26 kg; cost = ₹1,488. Clicks: 2,500 sheets × 2 sides = 5,000 clicks × ₹2.50 = ₹12,500. Setup ₹500. Total = ₹1,488 + ₹12,500 + ₹500 = ₹14,488. Per leaflet = ₹2.90.
Conclusion: offset is cheaper by about ₹4,523, or ₹0.91 per leaflet, on these assumptions. But cost alone is not the decision because the offset press would be run by a trainee.
2. The customer offers a 10% premium for three-day delivery. Evaluate the non-cost risks of each route and recommend which process to use.
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Offset risks: the trainee must run four passes on a two-colour press. Misregistration, inconsistent ink feed, poor spray-powder control, and set-off are all likely. Set-off is especially damaging because the customer rejects it. The pressroom is also booked for the first two days, so the five-day schedule is tight; a trainee error could lose the order.
Digital risks: toner gloss can differ from offset, and the customer rejects visible gloss difference. However, the owner can supervise, the job is one pass, there is no set-off, and three-day delivery is realistic. The click cost is higher by about ₹4,500.
Recommendation: use digital if the 10% premium covers a meaningful part of the extra cost and if the owner can check gloss on the actual 130 gsm art paper before running. If the premium is small, ask the customer to accept five days and use offset only with the owner or an experienced operator supervising make-ready and the first 200 sheets. Do not hand a four-pass brand-sensitive job to an unsupervised trainee.
3. If the shop chooses offset, list the control checks that must be in place before the first pass and between passes to prevent set-off and misregistration.
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Before the first pass: confirm plate register and punch fit, set ink keys to the proof, check fountain solution pH and conductivity, confirm paper grain direction, and print a 50-sheet test for colour and register. Record colour-bar densities.
Between passes: allow adequate drying, control stack height to about 500 sheets rather than 1,000, apply spray powder at the maker's rate, and check the reverse of the top sheets for set-off before loading the next pass. Keep the paper wrapped when idle to reduce moisture pickup. Re-register using the same gripper edge and check the first 20 sheets of every pass. If set-off appears, reduce stack height and ink film, and do not simply add drier.