10 sources, every one cited inline. The minute count you were given belongs to somebody else’s paper, sky and season. Your paper tells you when it is done, in colour.
Cyanotype on ready-coated paper — three projects and one recorded process
Because exposure is judged by colour, not by time. Ready-coated papers change colour as they expose, and each product changes differently — one fades toward white, another shifts from yellow-green to blue-grey. A borrowed minute count ignores your sky and your paper. Expose until your own product’s stated cue appears, then judge the print dry.
Written by Abdelmounim El Moussaddar · published by TopDigitalKnowledge · 31 pages · 4 illustrations
What everybody says
Cyanotype takes about fifteen minutes in full sun, so set a timer and come back.
What the evidence says
No single exposure time transfers between papers, let alone between skies. The Sunprint walkthrough gives 2–5 minutes in direct sun and 5–20 under cloud, watching the blue areas fade toward white; Cyanotype UK’s ready-coated paper instead starts yellow-green and goes blue-grey, and is washed until the yellow is gone and the water runs clear. Those are different products with different cues. And the colour you judge is not the colour you see wet: the blue deepens as the print dries and oxidises, so a pilot called a failure at the sink is often a pilot judged too early.
Until your paper does what its maker says it will do — which is a colour change, not a time.
The two cues in common use point in opposite directions. On Sunprint-type paper the exposed blue areas fade toward white, and the published walkthrough gives roughly 2–5 minutes in direct sun or 5–20 under cloud, with water processing of 1–5 minutes. On Cyanotype UK’s ready-coated stock the initial yellow-green coating turns blue-grey in the exposed areas, and the wash continues until the yellow has gone and the water clears.
Watch the wrong one and you will either pull the print half-exposed or leave it until the highlights have gone. This is why the guide opens by making you write your own product’s rules down on a single page before any sensitive paper is opened.
The timer still has a job. It records what you did, so a pilot can be repeated. It just does not decide when the print is finished.
Almost always because the specimen lifted away from the paper.
Cyanotype UK describes using a clear panel to hold objects in close contact with the sensitised sheet, and the reason is geometric: a leaf resting flat casts a sharp shadow, while a leaf held a few millimetres clear lets light creep under its edge. A specimen that lifts can produce a noticeably softer boundary than one resting against the paper.
So the fix is usually in the stack, not the exposure. The guide has you check the contact stack as a separate step — and warns against the obvious wrong answer, which is to solve thickness with force. A heavy stem pressed hard under glass does not flatten; it tents the sheet around itself and spoils everything nearby.
Choosing the specimen is part of the same decision. The University of Alaska Museum of the North recommends small, flat objects for sun prints, and a large bloom is often more useful as separated petals than as one bulky head.
The Huntington recommends practising the arrangement on ordinary paper before you open the sensitive stock, and it is the cheapest step in the process.
The reason is that sensitised paper starts working the moment it meets light. Every second spent nudging a frond into place is exposure you did not intend and cannot take back. Composing on a plain sheet cut to the same dimensions, with a light pencil boundary marking where the real sheet ends, moves all of that deliberation out of the timed part of the job.
It also changes what you are deciding. On the rehearsal sheet you can try three versions, photograph the one you want and keep it beside you. The guide treats the blue itself as part of the composition rather than a background, because in a photogram the arrangement is the picture — opaque areas tend toward pale shapes against the blue.
Because it is not finished. Cyanotype UK notes that the blue deepens during drying and oxidation, so the colour at the sink is not the colour you are judging.
This matters more than it sounds, because almost every bad decision in a first session is made wet: shortening the next exposure, lengthening the wash, abandoning a pilot that would have dried well. The guide asks for a single discipline — let the print dry completely, then read three things and record a short verdict.
The same rule governs comparison. Cyanotype UK’s step-test method compares exposure by evaluating the processed, dry result, and for a straightforward botanical session the book uses a pair of separate pilot sheets rather than moving a mask across a complex layout. One variable changes between A and B, and both are judged dry.
What it will not give you is a universal minute count to carry forward. A good pilot is a local reference for the setup that produced it.
Unbuffered, photo-safe materials in contact with the print, and no adhesive on the image.
This is the one part of the process where generic craft advice is actively wrong. Library of Congress guidance on photographs recommends photo-safe enclosures and specifically excludes alkaline-buffered paper enclosures for cyanotypes — so the “acid-free” label that is correct for most paper craft is not sufficient here, because many acid-free products are buffered. Ware’s conservation research sets out the same sensitivity to alkali and recommends unbuffered materials in direct contact.
In practice that means checking the actual housing specification rather than the front of the packet, mounting with photo corners rather than glue, handling by the edges and labelling the housing instead of the image.
It also means not treating a storage note as a repair manual. The guide is explicit that acid baths, deacidification and restoration treatments are not home procedures to attempt on the strength of a conservation footnote.
No, and this guide does not teach it. It is written entirely for commercially ready-coated paper, which you buy sensitised and use with its own printed instructions. Sensitiser mixing, coating raw paper, fabric printing, negatives, toning and UV-lamp work are all outside it.
It is designed to. The method is to identify your product, find its stated colour cue and wash instruction, write those on the one-page paper passport, and work from that. What it will not do is hand you one exposure time, because the two common paper families signal completion in opposite directions.
Suitable flat botanical material, a support board, an appropriate clear overlay to hold contact, a water-processing setup and an outdoor exposure site. All are bought separately; nothing physical is included with this download.
No. The four interior illustrations and the cover are illustrative images. They show arrangement and workspace ideas, not tested printing outcomes, and no exposure result should be inferred from them.
Follow the label on your paper. Jacquard cautions against ingestion, inhalation and skin contact with cyanotype materials and recommends adult supervision for children. The guide repeats that, and adds the ordinary craft precautions: equipment kept away from food, pets out of the work area, hands washed afterwards.
A single-frond botanical portrait, a coordinated three-print series that repeats a set of layout anchors while the shape varies, and a corner composition mounted as a removable card insert. Each has a design brief, a layout plan and a completion test.
Ten, all cited inline and all listed with links: the paper makers’ own instructions and FAQ, two museum teaching sheets, Library of Congress photograph-care guidance, a conservation chapter on cyanotypes, and the Met on Anna Atkins. These are instructions and conservation guidance rather than research literature, which is what this process actually runs on.
Nearly every cyanotype tutorial hands you a number of minutes. That number came from somebody else’s paper, latitude, hour and cloud, and it is the least transferable thing in the process. The ready-coated papers sold today each describe a colour cue instead — and they do not describe the same one. Sunprint-type paper fades toward white in the exposed areas; Cyanotype UK’s yellow-green coating turns blue-grey. Reading the wrong cue is the single most common reason a first print comes out flat or faint. 31 pages, three botanical projects, four printable records, and 10 references — the paper makers’ own instructions, two museum teaching sheets, and Library of Congress and conservation guidance on keeping the finished print.