{"course":{"slug":"vector-and-print","title":"Vectors, Logos and Things That Get Printed","url":"https://addaly.com/learn/vector-and-print","level":"beginner","track":"create"},"lesson":{"slug":"one-and-two-colour-work","title":"Getting a whole design out of two inks","url":"https://addaly.com/learn/vector-and-print/one-and-two-colour-work","position":33,"of":73,"minutes":8,"answer":"One plate gives five usable values including the reversed paper, and two inks give tints of each plus overprints, which is enough range for real work.","keyIdea":"One plate gives five usable values including the reversed paper, and two inks give tints of each plus overprints, which is enough range for real work, provided the colour count is decided before the design is drawn rather than after."},"body":{"format":"markdown","text":"## The constraint that improves the work\n\nA great deal of real print is one or two colours: letterheads, forms, invoice books, rubber stamps, screen-printed bags and shirts, newspaper advertising, cheap flyers, packaging for small producers. It is cheaper, it turns round faster, and the shops that do it are everywhere.\n\nIt is also where design gets interesting, because the constraint forces decisions.\n\n## The range available from one ink\n\nOne plate does not mean one tone. It means one hue at any percentage.\n\n- **100%**: the solid.\n- **60 to 70%**: reads as a distinctly lighter version, still confident.\n- **30 to 40%**: a background tone, still clearly the colour.\n- **10 to 15%**: a tint panel. Below this, dot gain and the press's minimum dot make it unreliable.\n- **Reversed**: the paper showing through a solid. This is your second \"colour\", free.\n\nFive values from one plate. Most one-colour work uses two of them and looks impoverished for no reason.\n\n## Two inks make more than two colours\n\nWith two plates you get: each ink's tint range, plus **overprinting**: one ink printed on top of the other, which mixes.\n\nA warm red and a deep blue overprinted give a dark plum. Tinted against each other (100% blue over 40% red, 40% blue over 100% red) give two more. A two-colour job can honestly show eight or nine distinguishable colours.\n\nTwo cautions, both real:\n\n- **The overprint colour is not predictable from the screen.** Transparent ink over transparent ink is not the same as a screen's multiply blend. Ask the shop to run a small overprint chart, or use one they already have.\n- **Ink sequence matters.** Blue over red and red over blue are not the same colour, because the first ink down is partly covered rather than fully transparent. The press decides sequence; ask.\n\n## Duotone for a photograph\n\nA photograph in one ink is a monotone: grey levels mapped onto one colour. Flat, and it loses shadow depth because one ink cannot reach a deep black.\n\nA **duotone** maps the image onto two inks with different tonal curves: typically black carrying the shadows and a colour carrying the midtones. The result has visibly more depth than either alone, and it is a genuine technique rather than a fallback.\n\nFree path, in GIMP: convert to greyscale, then Colours ▸ Map ▸ Gradient Map with a two-colour gradient, or use Colours ▸ Curves on separate channels after converting to RGB. Photopea has a Duotone mode under Image ▸ Mode. Krita has per-channel curves. None of these is as controllable as Photoshop's Duotone dialog with its per-ink curves, and all of them produce a usable result.\n\nFor a screen-printed job, remember that the two \"inks\" here become two screens, and the halftone angles must differ or you get moiré.\n\n## Designing for it from the start\n\nDecide the colour count **before** you draw. Retrofitting a four-colour design into two inks is a redesign, not a conversion.\n\nPractical rules:\n\n- Build everything from flat fills and tints of the two inks, named as swatches, from the first minute.\n- Set up your document with exactly two spot swatches and delete the rest. If you cannot pick a colour, you cannot use it.\n- Work in greyscale first for the tonal structure, then assign the two hues. The structure is what makes it work.\n- Keep a printed tint chart of your two inks beside you.\n\n## The economics, so you can advise a client\n\nA shop's quotation for a short run is dominated by setup, not by ink. Each additional plate adds plate cost, make-ready time, and a wash-up between jobs. On a 1,000-piece run, going from two colours to four can add a third to the price; on a 100,000-piece run the difference is small because setup is amortised.\n\nSo the honest advice to a small client is: **short run, few colours; long run, colours are cheap.** Being able to say that, with the reason, is worth more to them than any amount of styling.\n\nDigital presses change the arithmetic, and it is worth knowing which kind of machine a job is going on. A toner or inkjet digital press has no plates at all, so four colours cost the same as one and a run of fifty is viable. What it cannot do is spot inks, metallics, or the particular density of a solid litho colour. So the rule inverts: on digital, use all four colours freely and forget about plate counts; on litho, count the plates before you draw.\n\nAsk which press before you design. \"Is this digital or offset?\" is one line, and it changes the design brief rather than just the quotation."},"check":{"question":"A two-colour job is designed with a red and a blue spot, and the designer specifies a plum passage as red overprinting blue. The printed plum is lighter and pinker than the on-screen multiply preview. Why is this expected rather than an error?","options":[{"text":"Overprint preview in design software always previews the result at 100% opacity, regardless of the tint values that were actually set.","correct":false,"tempting":"Overprint preview does honour tint values. The mismatch is about ink physics, not about the preview ignoring percentages."},{"text":"The inks were printed in the wrong sequence, so the blue went down first when the design assumed red first.","correct":false,"tempting":"Sequence does change the result, but the mismatch with a screen preview would exist in either order: the screen model is the thing that does not match."},{"text":"Ink over ink is only partly transparent and depends on sequence; a screen's multiply assumes full transparency.","correct":true},{"text":"Spot inks cannot overprint at all, so the press knocked out the blue beneath the red and only the red printed.","correct":false,"tempting":"Spot inks overprint readily; that is the basis of two-colour work. A knockout would have shown pure red, not a plum at all."}]},"prev":{"slug":"spot-colours-and-plates","title":"A spot colour is a plate, and a plate is money","url":"https://addaly.com/learn/vector-and-print/spot-colours-and-plates"},"next":{"slug":"trapping-chokes-and-spreads","title":"Trapping, and the white line around everything","url":"https://addaly.com/learn/vector-and-print/trapping-chokes-and-spreads"},"authorship":"Founder and series editor: Dr Mustafa Mun. Written by AI models to a written standard. Exam keys checked blind by a second model: 3,665 of 3,666 agreed. Academic review invited.","review":{"status":"Draft, open for academic review"},"cite":"Addaly (2026) 'Getting a whole design out of two inks', in Vectors, Logos and Things That Get Printed. Edited by M. Mun. Addaly. Available at: https://addaly.com/learn/vector-and-print/one-and-two-colour-work (Accessed: 13 October 2026).","licence":{"name":"CC BY-NC-SA 4.0","url":"https://creativecommons.org/licenses/by-nc-sa/4.0/"},"reader":{"schema":1,"title":"Getting a whole design out of two inks","courseTitle":"Vectors, Logos and Things That Get Printed","module":{"index":4,"slug":"colour-for-print","title":"Colour that survives the press"},"answer":null,"keyIdea":"One plate gives five usable values including the reversed paper, and two inks give tints of each plus overprints, which is enough range for real work, provided the colour count is decided before the design is drawn rather than after.","hero":{"kind":"plate","image":null,"alt":null,"caption":null},"blocks":[{"t":"h2","id":"the-constraint-that-improves-the-work","runs":[{"text":"The constraint that improves the work"}]},{"t":"p","runs":[{"text":"A great deal of real print is one or two colours: letterheads, forms, invoice books, rubber stamps, screen-printed bags and shirts, newspaper advertising, cheap flyers, packaging for small producers. It is cheaper, it turns round faster, and the shops that do it are everywhere."}]},{"t":"p","runs":[{"text":"It is also where design gets interesting, because the constraint forces decisions."}]},{"t":"h2","id":"the-range-available-from-one-ink","runs":[{"text":"The range available from one ink"}]},{"t":"p","runs":[{"text":"One plate does not mean one tone. It means one hue at any percentage."}]},{"t":"ul","items":[[{"text":"100%","b":true},{"text":": the solid."}],[{"text":"60 to 70%","b":true},{"text":": reads as a distinctly lighter version, still confident."}],[{"text":"30 to 40%","b":true},{"text":": a background tone, still clearly the colour."}],[{"text":"10 to 15%","b":true},{"text":": a tint panel. Below this, dot gain and the press’s minimum dot make it unreliable."}],[{"text":"Reversed","b":true},{"text":": the paper showing through a solid. This is your second “colour”, free."}]]},{"t":"p","runs":[{"text":"Five values from one plate. Most one-colour work uses two of them and looks impoverished for no reason."}]},{"t":"h2","id":"two-inks-make-more-than-two-colours","runs":[{"text":"Two inks make more than two colours"}]},{"t":"p","runs":[{"text":"With two plates you get: each ink’s tint range, plus "},{"text":"overprinting","b":true},{"text":": one ink printed on top of the other, which mixes."}]},{"t":"p","runs":[{"text":"A warm red and a deep blue overprinted give a dark plum. Tinted against each other (100% blue over 40% red, 40% blue over 100% red) give two more. A two-colour job can honestly show eight or nine distinguishable colours."}]},{"t":"p","runs":[{"text":"Two cautions, both real:"}]},{"t":"ul","items":[[{"text":"The overprint colour is not predictable from the screen.","b":true},{"text":" Transparent ink over transparent ink is not the same as a screen’s multiply blend. Ask the shop to run a small overprint chart, or use one they already have."}],[{"text":"Ink sequence matters.","b":true},{"text":" Blue over red and red over blue are not the same colour, because the first ink down is partly covered rather than fully transparent. The press decides sequence; ask."}]]},{"t":"h2","id":"duotone-for-a-photograph","runs":[{"text":"Duotone for a photograph"}]},{"t":"p","runs":[{"text":"A photograph in one ink is a monotone: grey levels mapped onto one colour. Flat, and it loses shadow depth because one ink cannot reach a deep black."}]},{"t":"p","runs":[{"text":"A "},{"text":"duotone","b":true},{"text":" maps the image onto two inks with different tonal curves: typically black carrying the shadows and a colour carrying the midtones. The result has visibly more depth than either alone, and it is a genuine technique rather than a fallback."}]},{"t":"p","runs":[{"text":"Free path, in GIMP: convert to greyscale, then Colours ▸ Map ▸ Gradient Map with a two-colour gradient, or use Colours ▸ Curves on separate channels after converting to RGB. Photopea has a Duotone mode under Image ▸ Mode. Krita has per-channel curves. None of these is as controllable as Photoshop’s Duotone dialog with its per-ink curves, and all of them produce a usable result."}]},{"t":"p","runs":[{"text":"For a screen-printed job, remember that the two “inks” here become two screens, and the halftone angles must differ or you get moiré."}]},{"t":"h2","id":"designing-for-it-from-the-start","runs":[{"text":"Designing for it from the start"}]},{"t":"p","runs":[{"text":"Decide the colour count "},{"text":"before","b":true},{"text":" you draw. Retrofitting a four-colour design into two inks is a redesign, not a conversion."}]},{"t":"p","runs":[{"text":"Practical rules:"}]},{"t":"ul","items":[[{"text":"Build everything from flat fills and tints of the two inks, named as swatches, from the first minute."}],[{"text":"Set up your document with exactly two spot swatches and delete the rest. If you cannot pick a colour, you cannot use it."}],[{"text":"Work in greyscale first for the tonal structure, then assign the two hues. The structure is what makes it work."}],[{"text":"Keep a printed tint chart of your two inks beside you."}]]},{"t":"h2","id":"the-economics-so-you-can-advise-a-client","runs":[{"text":"The economics, so you can advise a client"}]},{"t":"p","runs":[{"text":"A shop’s quotation for a short run is dominated by setup, not by ink. Each additional plate adds plate cost, make-ready time, and a wash-up between jobs. On a 1,000-piece run, going from two colours to four can add a third to the price; on a 100,000-piece run the difference is small because setup is amortised."}]},{"t":"p","runs":[{"text":"So the honest advice to a small client is: "},{"text":"short run, few colours; long run, colours are cheap.","b":true},{"text":" Being able to say that, with the reason, is worth more to them than any amount of styling."}]},{"t":"p","runs":[{"text":"Digital presses change the arithmetic, and it is worth knowing which kind of machine a job is going on. A toner or inkjet digital press has no plates at all, so four colours cost the same as one and a run of fifty is viable. What it cannot do is spot inks, metallics, or the particular density of a solid litho colour. So the rule inverts: on digital, use all four colours freely and forget about plate counts; on litho, count the plates before you draw."}]},{"t":"p","runs":[{"text":"Ask which press before you design. “Is this digital or offset?” is one line, and it changes the design brief rather than just the quotation."}]}],"check":{"question":[{"text":"A two-colour job is designed with a red and a blue spot, and the designer specifies a plum passage as red overprinting blue. The printed plum is lighter and pinker than the on-screen multiply preview. Why is this expected rather than an error?"}],"options":[{"text":[{"text":"Overprint preview in design software always previews the result at 100% opacity, regardless of the tint values that were actually set."}],"correct":false,"tempting":[{"text":"Overprint preview does honour tint values. The mismatch is about ink physics, not about the preview ignoring percentages."}]},{"text":[{"text":"The inks were printed in the wrong sequence, so the blue went down first when the design assumed red first."}],"correct":false,"tempting":[{"text":"Sequence does change the result, but the mismatch with a screen preview would exist in either order: the screen model is the thing that does not match."}]},{"text":[{"text":"Ink over ink is only partly transparent and depends on sequence; a screen’s multiply assumes full transparency."}],"correct":true,"tempting":null},{"text":[{"text":"Spot inks cannot overprint at all, so the press knocked out the blue beneath the red and only the red printed."}],"correct":false,"tempting":[{"text":"Spot inks overprint readily; that is the basis of two-colour work. A knockout would have shown pure red, not a plum at all."}]}],"order":[0,3,2,1],"why":null},"prev":{"slug":"spot-colours-and-plates","title":"A spot colour is a plate, and a plate is money","minutes":9},"next":{"slug":"trapping-chokes-and-spreads","title":"Trapping, and the white line around everything","minutes":8}}}