What is DL size?

Where the numbers come from

The A series of ISO 216 halves as it goes down, and DL sits outside that halving. It is a third of A4 instead of a half: divide the 297 millimetre long side of A4 into three and you get panels 99 millimetres wide and 210 tall. The envelope is slightly larger to leave room for the folded paper. Markus Kuhn's widely cited notes on the ISO paper formats, hosted by the University of Cambridge, give the DL envelope as 110 by 220 millimetres, sized to hold A4 folded twice, and suggest the name probably began as DIN lang, the long German format. Because DL shares its 210 millimetre height with both A4 and A5, one DL flyer stands exactly as tall as an A4 page turned sideways.

Why the shape changes the design

DL is a narrow column, roughly two to one. A layout that works on A4 cannot simply be shrunk to fit, because A4 is a wider rectangle and scaling it into DL either leaves wide empty bands or crops the sides. The content has to be rearranged into a single column read from top to bottom. That usually suits a flyer well: a headline at the top, an image or a short list in the middle, and the phone number or web address at the foot where the hand holding it does not cover it. It suits text heavy material less, since a line of type across 99 millimetres holds only a few words at a readable size, so long paragraphs turn into narrow ribbons.

When DL is the right choice

DL is the default for anything that travels in an envelope or sits in a display rack: brochures in a tourist information stand, a price list tucked in with an invoice, a menu left at a front door, a leaflet handed out at a market stall. It also posts cheaply. Australia Post defines a small letter as up to 130 by 240 millimetres, 5 millimetres thick and 250 grams, which a DL envelope fits comfortably. For letterbox drops, DL and A5 are the common choices; DL is cheaper per piece and easier to push through narrow slots, while A5 gives an image room to breathe. A folded DL brochure made from an A4 sheet, known as a trifold, is the other everyday use.

Common mistakes

The most common is taking an A4 design and asking the printer to fit it to DL, which produces tiny text or a cropped layout. The second is ignoring the edges: a narrow format has proportionally more of its area near a trim line, so keep text and phone numbers a few millimetres in from every edge, and extend backgrounds past the edge if the shop asks for bleed. The third is mixing up the flyer and the envelope sizes; artwork supplied at 110 by 220 millimetres will be trimmed or rejected for a 99 by 210 flyer. The last is writing too much. A DL flyer is read in a few seconds, and one offer with one way to act is usually all it can carry.

DL and the flyer builder

DL is not one of the eight canvas sizes in the flyer builder, which offers A4 portrait at 1240 by 1754 pixels, A4 landscape at 1754 by 1240 and six social sizes, with no custom size. The nearest print export is A4 at 2480 by 3508 pixels, which is A4 at 300 DPI. There is a practical route because of the geometry above. A4 landscape divided into three equal panels gives panels about 585 pixels wide and 1240 tall, which is DL at 150 DPI, and the export doubles that. Build three DL flyers side by side on an A4 landscape page, marking the lines at 584 and 1169 pixels with thin shapes you delete before export, and ask the print shop to cut the sheet into thirds. There are no fold or cut guides, so the positions are yours to place.

Questions people ask