Registration that holds

Registration is the problem of putting the same sheet of paper back in the same place, pass after pass. Get it slightly wrong and a multi-colour print shows a pale rim of the paper, or one colour drifting off another, instead of colours meeting cleanly.

Ways to hold a sheet in place

Kento is the traditional Japanese registration system: a right-angled notch cut into the corner of the block to hold two edges of the paper, and a second, straight notch further along one side to hold it against rotating. Kento is cut into the block itself, so it travels with the block for the whole run.

Ternes-Burton pins and tabs register against the block's baseboard rather than the block: two small pins are fixed to the board, and a paper or plastic tab is punched and taped to the back of each sheet, so every sheet drops onto the same two pins in the same place. Useful when you're printing from more than one block on the same run, since the pins stay put and the blocks move.

A T-bar is a guide taped to the printing surface in the shape of a T, against which two edges of the paper are butted for each pull. Simple to make, and easy to reposition if your setup changes mid-run.

Corner tabs are the least equipment: small paper or tape flags fixed to the printing surface marking where two corners of the sheet land. Quick to set up, less forgiving if the surface shifts.

None of these is universally "correct." Many printmakers pick a system based on the block, the press (or lack of one), and habit, and mix approaches, cutting kento into the block but also taping a tab as a backup mark.

Paper and damp

Registration drifts if the paper itself changes shape between passes. Paper that's dampened for one pass and dry for the next will have moved, sometimes only slightly, sometimes enough to see. If you dampen paper for one pass, most printmakers dampen the whole stack the same way for every pass of that print, and note it, so a second printing session doesn't accidentally mix damp and dry sheets. Grain direction matters too: cut or tear a stack of paper together, before you start, so every sheet expands and contracts the same way.

Test on the ghost

Before you commit a real sheet to a new stage, print it onto a ghost, the faint second pull taken without re-inking a proof from the previous stage. It costs you nothing but a moment, and it tells you whether your registration marks for the next pass actually line up before you risk the sheets you care about. If you carve on the iPad app, Carve Plan can generate a kento, Ternes-Burton, T-bar, or corner-tab jig at true size straight from your separations. See Carve plan.