A duffel, a dopp kit and a messenger bag are the same bag at different sizes with different lids. This pattern treats them that way: set the finished dimensions, choose a zip top or a lined flap, then switch on a shoulder strap, grab handles or a front pocket. The hardware list and assembly steps update with your choices.
OPEN THE PATTERN TOOL →The body is a single wrap panel that runs up the front, under the base and up the back, with a set-in end panel at each side. That construction is why the print on a patterned fabric can run continuously around the bag. Two identities keep it honest: the end panel perimeter has to equal the wrap ends plus the top, and on a zip top the two zip strips plus the exposed zipper have to add up to the depth. Both are shown live while you drag.
You can adjust width (zip run), height, depth, zip exposure, flap drop, seam allowance. The pattern has 6 piece types and 8 assembly steps, all of which update with your numbers.
| FINISHED | 55 cm × 28 cm × 26 cm |
| MAIN WRAP CUT | 57 cm × 84 cm |
| END PERIM CHECK | 108 cm = wrap ends + top |
| ZIPPER | ≥ 55 cm usable |
| STRIP CHECK | 2×12.6 cm + 8 zip = 26 cm |
| WEBBING (STRAP) | 38 mm × 150 cm |
| WEBBING (HANDLES) | 25 mm × 172 cm total |
| HARDWARE | #8 zip + 2 rect rings 38mm + slider + 2 snap hooks |
| SEAM ALLOW | 10 mm |
| FABRIC (112cm W) | ~154.8 cm |
| PRINT SHEET | tile at home or roll print |
Those are the starting numbers. Change any of them in the tool and everything above recalculates, including the fabric estimate and the sheet size.
A tiled PDF for home printing on Letter or A4, laid out at true scale with a 50 mm calibration square and a page map, or a full-scale SVG sized in real millimetres for projector sewing and cutting machines. Everything is free, with no account and no email address.
Print at 100% scale and never use "fit to page". Measure the calibration square before you cut anything: if it measures 50 mm, the rest of the pattern is right.
Heavy canvas, cordura or waxed cotton, with webbing for the strap and handles. A large duffel needs roughly 1.5 metres of 112 cm fabric. Interface everything unless the fabric already stands on its own.