Printers will happily debate digital versus offset for hours. As someone who cares mostly about what shows up in mailboxes and what it costs, I can compress the debate: for the campaign sizes most businesses actually send, digital printing wins, and the reason is not just price.
The one-minute technical difference
Offset presses transfer ink from etched plates. Making plates costs real setup money, but once a press is running, each additional copy is very cheap. Digital presses work like extremely good production inkjets and toner systems: no plates, no setup, the first copy costs the same as the ten thousandth.
That cost structure creates a crossover point. Below it, digital is cheaper. Above it, offset wins on unit price. For direct mail formats, that crossover generally sits in the tens of thousands of pieces, which means the typical local campaign of 500 to 20,000 pieces lives comfortably in digital territory.
Quality stopped being the argument
A decade ago, offset had a visible edge on photo work. Modern production digital presses closed most of that gap, and at postcard viewing distance in a kitchen, your recipients cannot tell. What they can tell is whether the piece speaks to them, which brings us to the real reason digital wins.
Personalization is the tiebreaker
An offset plate prints one image thousands of times. A digital press can change every single impression, which is what makes variable data printing possible: each recipient's name, offer, nearest location, and their own unique QR code, printed in one run at full speed.
Industry research compilations report meaningful response lifts from personalization, with VDP studies showing multi-fold improvements over static creative. Whatever the exact lift in your niche, the mechanism requires digital. Offset physically cannot print 5,000 different QR codes in a run.
My rule of thumb: under roughly 50,000 pieces, or any volume where per-recipient tracking and personalization matter, go digital. Reserve offset for huge, identical, brand-blast runs. Since Relay puts a unique tracked QR on every piece, every campaign we touch is a digital print job by definition, and the economics work all the way down to a 200-piece farm mailing.