Designing for two inks

Pick inks first, design second

In CMYK you design any color and the machine finds it. In riso you pick from the shelf, currently eleven inks, and the overlap of two is your third color for free. This is not a limitation to route around, it is the whole aesthetic. A pink-and-blue job has three colors: pink, blue, and the violet where they meet. Design the violet on purpose.

Practical rule: open the ink library, choose two inks, and put their actual values in your file as spot channels. Never design in RGB and hope. The shelf is small, and that is why every job that follows the rule looks like it belongs to this studio and nowhere else.

Type rules the drum enforces

Sans-serif type survives down to about 6pt in one color. Serifs start closing up below 8pt. Reversed type (paper-colored letters in an ink field) needs to be at least 10pt bold or it fills in, because the ink spreads a touch as it soaks.

Two-color text is a special trap: never overlay two inks on small type expecting alignment. The passes will drift and your type will gain a chromatic shadow. That shadow is gorgeous at display sizes and fatal at body sizes. Body text: one ink. Headlines: go wild.

Photographs become halftones

Convert photos to bitmaps at 600 dpi before they reach us. The threshold you pick is the creative decision: high threshold keeps shadow detail and loses highlights, low does the opposite. For two-ink duotones, separate the photo into two bitmaps by luminosity, assign one per ink, and let the overprint make the midtones.

The workshop on this subject runs every few months because it is genuinely two hours of material. Bring your own photo to Halftone Photography on the Drum and leave with a print of it.

Gradients: build them from dots

Smooth gradients die on a drum: anything below about 15% dot size drops out entirely, and above about 85% it fills in. Build gradients as visible dot ramps instead, halftone sizes 4 through 7, and they will print exactly as designed. A gradient that pretends to be smooth always betrays you. A gradient that admits it is dots becomes texture.

Give the inks room to disagree

Expect plus or minus a millimeter of drift between passes, sometimes two on big solids. Design decisions that make drift invisible: quarter-inch overlap where two colors meet, thick keylines around overlapping shapes, textures instead of hairlines at color boundaries. Decisions that make drift catastrophic: hairline knockout type, thin parallel color bands, tight-trimmed duotone portraits.

When a design needs perfect registration, we say so at the consult and show you what the machine does instead. Usually the alternative is better. That is not a sales line, it is nine years of data.

Bleed, feed margins, and the ugly truth

Standard bleed is 0.125 inches. The feed margin is the catch: the machine's grippers hold the leading edge, so full ink coverage on all four sides needs a trim. We print oversized and cut down, which adds a day. For work that bleeds on three sides only, no trim is needed and the job stays cheap. Know which edges matter before you design the layout.

File structure that keeps masters honest

One layer or spot channel per ink color, named for the ink, nothing else in the file. Put a rectangle of 100% K on each layer as a registration mark outside trim; we align by them. Text should be outlined or accompanied by the font files. Flatten nothing: we may need to adjust a separation, and a flattened file takes design hours to fix.

Proofs are pulled, not promised

We pull a free proof of every color pass. Approve it in person or by photo, and understand what approval means: the drift you see is the drift you get. Once the run starts, changing your mind costs a master burn, which is real money and a real apology from whoever burns it. Look at the proof like it is the artwork, because it is.

Paper changes everything, so pick it early

The same two inks read completely differently on cream cotton, peach cover, and grey text. Paper is not a printing decision, it is a design decision, and it should happen before layout. The paper library page shows every stock with its temperament, and the drawer by the door holds a sample of each. Come touch them. Trust your hands over any description, including this one.

The real timeline of a two-color job

Day one: consult and file check, book the slot. Day two: masters burned in the morning, color one runs, stack rests overnight. Day three: color two, rest, count, band. Pickup or shipping day four. This is why the turnaround is 48 hours plus drying and not a marketing number. Rushing riso produces smears, and smears are only cool when they are intentional.