← Cut & Proof

Reduction
Ladder

One block, printed again and again, cutting more away each time. Get the order wrong and the block is gone. This plans the whole run before the first cut — including the ink you actually have to mix, which is rarely the colour you can see.

To keep this on your home screen: tap the Share button in Safari, then Add to Home Screen. It will then open full screen and work without a signal.

The print
Working
Start with a picture

Choose a photo or drawing, drag one onto this panel, or paste one straight from your clipboard.

Take it off the screen

The bench sheet is the one to pin above the press — every stage, its ink, and what to cut before it.

The plan

What you are printing

The run

The blocks

The key block

Ink and paper

This sets everything at once. Each pass or block can then be adjusted on its own below — few printmakers use the same mix throughout.

How this works

The short version

Reduction printing is one block, printed over and over, with more cut away each time. You cannot put lino back, so the order is fixed: lightest first, darkest last. Give this a picture and a number of passes and it works out the whole run — what the block looks like at every stage, what to cut before each pass, and crucially what ink to mix.

The example

Try an example loads The Great Wave off Kanagawa by Katsushika Hokusai, about 1831. It is a useful thing to practise on: broad flat areas that reduce cleanly, and a limited palette that was itself printed from woodblocks, one colour at a time — which is very close to what this tool is planning.

The print is long out of copyright and the Metropolitan Museum of Art has released its scan into the public domain, so it travels with the app. It is stored inside the page itself, which is why the example still works with no signal.

Two ways to print in colour

The switch at the top of the plan chooses which job you are doing.

  • Reduction \u2014 one block, printed again and again, cutting more away each time. Cheap in materials and beautiful, but unforgiving: you cannot put lino back, so when the edition is printed the block is gone and cannot be reprinted.
  • Multi-block \u2014 a separate block for each colour. More cutting, and the registration has to be right, but nothing is irreversible and you can pull the edition again next year.

Blocks that overprint, and blocks that do not

In multi-block, the important choice is whether blocks are allowed to print on top of one another.

Not overprinting means each block carries its own areas and they butt together. Three blocks give three colours. Simple to plan, simple to judge, and the registration is forgiving because nothing has to line up on top of anything.

Overprinting means a yellow block under a blue block makes green. Three blocks can then give seven colours plus the bare paper \u2014 the same three cuts doing far more work. The tool works out every combination your inks can produce and matches the picture to them. This is where multi-block earns its keep, and it is also where the registration has to be honest.

The tool will tell you what you are giving up: switch overprinting off and it says how many colours the same blocks could have made.

Choosing the inks

Press Choose the inks for me and it searches for the set whose combinations cover your picture best. This rarely lands on the colours you can see in the image \u2014 the right inks for overprinting are the ones that make good colours when laid over each other, which is a different question. Open any block and change its ink if you disagree; everything re-solves around your choice.

Trapping, and why your blocks should be too big

Two blocks that meet exactly will show a white line the moment the paper lands a hair off \u2014 and it always does. Trap makes every block except the last slightly too big, so neighbours overlap by a whisker. Misregistration then eats into the overlap instead of opening a gap. The last block is never spread, because it prints on top and growing it would smear the design.

0.3 to 0.5mm suits most hand printing. Raise it if your registration is rough.

Registration marks

Each exported mask carries a cross in a circle at all four corners, outside the image area and identical on every block. Line the marks up and the image lines up. They are deliberately simple: for a real jig \u2014 kento notches, pin registration, an L-corner board \u2014 that is Kento\u2019s job, and it does it properly.

What a pass actually is

Each pass is one round of cut, then print, in that order:

  • Cut away the area shown in mid grey on the mask — that is the part which has just reached its final colour, so it must never take ink again.
  • Print the whole block in that pass's ink. Everything still standing takes the new colour.

So pass 1 normally has nothing to cut: the block is whole and you print the lightest tone across all of it. From pass 2 onwards there is always something to remove first.

If that lightest tone is barely different from your paper, printing it is a wasted session. Tick leave the lightest as bare paper and it is dropped — the paper does that job, and your first pass now begins with a cut. The number of passes you set stays the same either way; the tool simply finds one more tone to give to the paper.

On the mask, black is lino still standing and about to print, red is what to cut away before this pass, and white is what went in earlier sessions. If you only ever look at one thing, look at the red.

Why the ink is not the colour you see

Every pass prints on top of the last. Unless your ink is completely opaque, what lands on the paper is a combination of the new ink and everything under it. So the ink you mix is not the colour you want to end up with — it has to allow for what is already there.

Each rung shows two swatches: the ink you mix on the left, what it gives you on the paper on the right. With opaque ink they will look the same. Wind the transparency down and watch them separate. That gap is the thing this tool exists to work out.

Transparency

The slider runs from fully opaque to a pure glaze.

  • Opaque — straight ink, covering what is underneath. The plan is honest as drawn, and the tool's value is the sequencing and the masks.
  • Transparent — ink cut with extender or transparent base. It tints what is below rather than covering it. This is where reduction printing gets its glow, and where the ink you mix goes somewhere you would never guess.

Set them all at once at the top, then adjust each pass on its own. Nobody prints every layer at the same consistency, and a first pass laid down solid followed by glazes is a common way to work.

When it says something cannot be done

A transparent ink can only ever darken what is underneath. There is no such thing as an ink brighter than white, so once an area is dark you cannot bring it back up.

If a pass needs an ink lighter than the paper can give, the rung turns red and says so plainly. Your options are to make that pass more opaque, to reorder or re-choose your colours, or to accept the darker result. It will show you the closest it can actually get either way.

You may also see barely different from the pass before. That is a whole session of cutting and printing for a change nobody will see — usually a sign to drop a pass.

Reading the block

  • The print so far — what the paper looks like after this pass.
  • The block now — what is still standing, dark, before this pass is printed.
  • Cut first — what to gouge away before this pass is printed, in registration red. This is the one to work from at the bench, and it matches the grey area on the printed mask exactly.
  • Original — the picture you started with, for comparison.

Each rung also gives a carve area: roughly how much of the block that session removes, as a percentage. Useful for judging whether it is an evening's work or twenty minutes.

Mixing the ink

Every rung has a Mix this button that opens Mixing Slab with that ink colour already loaded, so it can work out the recipe from the tubes you actually own. It opens in a new tab and your plan stays put.

Getting it to the bench

Print the bench sheet gives you the whole run on paper: every pass, both swatches, the ink code, the carve area and any warnings. Pin it above the press.

Download cut masks saves a PNG per pass at your chosen printed size, in the same three tones: black still standing, red to cut away now, white already gone. On a black-and-white printer the red comes out as a mid grey, which still reads clearly.

What it can't do

  • Know your ink. Transparency is a slider, not a measurement. Pull a proof.
  • Model your paper properly. It assumes an even, non-absorbent sheet. Damp or heavily sized paper behaves differently.
  • Account for ink film thickness. A heavy roll-up covers more than a thin one, and no slider knows how hard you push.
  • Make it a good print. It divides tone honestly. Whether five colours in that order make a picture worth pulling is entirely yours.

Where your data lives

Your settings are saved in this browser. Your picture is not saved at all — it stays in memory while the tab is open and goes when you close it. Nothing is ever uploaded.