← Cut & Proof

Kento

Getting every block to land in the same place. Give it your paper, your image and your blocks, and it works out the registration for you — a two-pin jig you build once, or traditional kento notches cut into the blocks themselves — and prints the templates at full size.

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How this works

The short version

Two pins fix a sheet of paper completely — where it sits, and which way round it is. Punch two holes, drop the sheet over the pins, and it lands in exactly the same place every time. Do the same for the block with a pair of stops, and every colour prints where it should.

This works out where all of that goes, and gives you a template to drill through.

Punched paper, or tabs

  • Punched paper puts two holes through the sheet itself, in a margin you either keep or trim off. Cheap — an office two-hole punch and two lengths of dowel. The cost is holes in your print.
  • Tabs put the holes on a strip of mylar or card taped along the edge of the sheet, so nothing pierces the print. More faff, and something to buy, but the sheet comes off clean.

Why the block needs stops too

Pins only solve half the problem. If the paper lands perfectly but the block has shifted a millimetre, you have still lost registration. Two battens screwed down in an L put the block back in the same corner every time.

Blocks that are not all the same size

A stop cannot move. So a block cut a little smaller registers by its corner, and its image lands off to one side by the whole difference — not half of it. The tool sets the stops for your biggest block and then tells you how much to pack the others out: half the difference against each stop. Thin card or mountboard does it.

If that sounds like a bodge, it is worth saying plainly that the alternative is cutting every block to the same size before you start, which is the better answer when you can manage it.

What it warns you about

  • Punch holes that would land inside the image area
  • Pins standing taller than the block, so the paper tents instead of lying down
  • A block smaller than the image you have asked it to carry
  • A block that reaches past the pins and would sit on top of them

Printing the template

A jig bigger than a sheet of A4 has to be tiled, so you get several sheets to trim and tape together. Set your printer to 100% or actual size — not "fit to page", which is usually the default and will quietly shrink everything.

Every sheet carries a 100mm scale bar. Measure it before you drill. If it is not 100mm, the print scaled and nothing else on the sheet can be trusted.

The dimensioned drawing is the other way to work: one sheet, not to scale, with every position listed in millimetres from the bottom-left corner of the board. Mark it out with a rule and a square. For a big board that is often quicker than taping eight sheets of paper together.

Kento notches

The traditional Japanese method, and the one this tool is named after. Nothing to build and nothing to buy: two small guides are cut into every block of the set.

  • The kagi is a right-angled guide at one corner — traditionally the lower right. The corner of the sheet goes into it.
  • The hikitsuke is a straight guide along the same edge, a short way in from the far corner. The edge of the sheet lies along it.

Two contacts on one edge and one on the other fix the sheet completely. The further apart those two edge contacts sit, the better they hold it straight.

The bit that surprises people

The guides are not grooves cut for the paper to drop into. They are small ridges of wood left standing in a margin that has been cleared away around them. The paper lies on the block, its edge reaches out across the shallow cleared strip, and it stops against the inner face of the ridge.

The tops of the ridges are then shaved a fraction below the face of the block, so the baren passes over them without catching.

How deep to clear

Shallower than you would think. Toshi Yoshida gives it as two to three times the thickness of the paper — for ordinary thin washi that is a few tenths of a millimetre, not millimetres. That is why the tool asks for your paper thickness and works the depth out for you rather than letting you type a number.

Be aware that the sources disagree here. Beginner woodblock kits often teach a clearing of a single paper thickness, which is shallower again. That is probably right for what those kits are: two blocks, dry paper, one afternoon. Yoshida is describing full professional practice, where the sheet is damped and handled many times over. This tool uses two and a half times because it is built for multi-block and reduction work, but if your print is simple and your paper is dry, less is no error. Flat and smooth matters far more than the exact figure — check it against a folded scrap of your actual paper, not a ruler.

The first cut, made straight down on the line with the chisel held upright, is deeper — about a millimetre and a half. That gives a clean wall for the paper to meet. The clearing that follows is the shallow part.

Blocks that are not all the same size

With pins this is a nuisance and needs packing strips. With notches it simply is not a problem: the guides are positioned from the image and cut into each block separately, so mismatched blocks still register perfectly. Each block only has to be big enough on its own.

It does have to be bigger than the paper, though, because the guides live in the margin outside the sheet. If it isn't, the tool will say so and offer to size the blocks for you.

Damp paper

Moku hanga is printed damp, and damp paper is bigger than dry paper — often by several millimetres on a large sheet, and more across the grain than along it. The tool does not guess at that, because the figure depends on your paper, how long it has been damped and which way the grain runs. Damp a sheet, let it settle, measure it, and type that size in.

Getting the same notches on every block

Traditionally the kento cut on the key block was printed onto the proofs, and those proofs were pasted onto every colour block — so the marks copied themselves across the set. The 1:1 transfer template is the same trick by other means. Print one per block, tape it down, and prick through. Do not measure each block separately; that is how small errors get in.

The paper calculator

Given a full sheet and a size you want, it tries every sensible guillotine layout — all one way up, all the other, and the two ways of splitting the sheet and turning the pieces in one part — and reports whichever yields most.

Grain matters because damp paper stretches across the grain far more than along it. Cut half an edition one way and half the other and they will not behave the same on the press. Tell it which way the grain runs in the parent sheet and it will tell you which way it ends up in each piece.

What this does not do yet

L-corner jigs and hinged mylar registration are both planned. Hinged mylar in particular is how most reduction lino gets registered, and it is next.
The jig

Two pins and a punched sheet. The paper and the block are both held by a jig you build once and keep.

Paper

mm

Image area

mm
Centred puts equal margins all round. Optically centred makes the bottom margin half again as deep as the top, which is the traditional look — a print centred by measurement appears to sag on the sheet. Margins I type lets you set the left and bottom yourself.

Prints per block

A block big enough for two or four sheets is worth using properly: carve them side by side, print them, cut them apart. Each print gets its own registration. Only prints at the outside of the block can carry kento notches, because the cleared area has to run off the edge for the sheet to slide in — the tool will tell you if one ends up hemmed in.

Blocks

Blocks cut to identical sizes register perfectly off one pair of stops. If yours came off different offcuts, choose No and enter each one — the tool will set the stops for the biggest and tell you how much to pack the rest out.

Pins

mm
mm
How far the hole centres sit from the edge of the paper. A standard office punch is 12mm. Only used when you are punching the paper itself.
How far the pin stands proud of the board. It has to be shorter than your block, or the paper will bridge over the pins instead of lying down on the inked surface.
How far past the edge of the paper the holes sit. The tab is taped along the paper's edge and the holes ride clear of the sheet, so nothing is punched through the print itself.

Board and stops

mm
The two strips of wood that form the corner the block sits into. Anything straight and stable does — 12mm ply, hardwood strip, even a length of aluminium angle. It only has to be thinner than the block.
The plan
Board Paper Image Block Pins & drill points
—

    Measured from the bottom-left corner of the board

    Print

    Saved jigs

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    Cutting paper down
    mm
    mm
    Paper fibres mostly lie one way. Damped paper stretches across the grain far more than along it, so a sheet cut the wrong way fights you on the press and will not shrink back to match the rest of the edition. The direction is usually printed on the ream label; if the wrapper has gone, tear a scrap both ways — it tears straight along the grain and ragged across it.

    —pieces per sheet