This is the record for the sheet you bought: which original it comes from, how it was digitised, what we did to the file, and what we are allowed to sell. Nothing here is marketing. It is the paperwork.
The sheet you have
- Work
- Anna Atkins, Polysiphonia fastigiata, cyanotype, 1853
- Object
- Plate from Photographs of British Algae: Cyanotype Impressions
- Held by
- The New York Public Library, Spencer Collection
- Accession
- NYPL Digital Collections, image 419600
- File
- iiif.nypl.org/iiif/3/419600 — 5595 × 7150 px
- Crop
- [112, 107, 5595, 7052] → 5483 × 6945 px, ratio 1.2666
- Printed at
- 653 dpi at 30 × 40 cm · 332 dpi at 50 × 70 cm
Which impression, and why this one
Atkins made her algae books by contact printing: the specimen laid straight onto sensitised paper, sunlight doing the rest. There is no negative and no plate, so every page in every copy is its own object. The NYPL copy is the one with the Herschel provenance — the set Atkins sent to John Herschel, who had given her the cyanotype process in the first place.
We looked for a better file and closed the search on 2 September 2026. The Metropolitan Museum's scan of the same subject is too small to print at 50 × 70 cm. The Rijksmuseum has a fine file, but it resolves to roughly 200 dpi at 42 cm and — more to the point — it is a different impression from a different copy, which would break the provenance line this record describes. The NYPL file stays.
What we measured
One finding belongs on the record because you can see it in the print: the right edge of the album leaf is not in the digitisation. Our crop's right boundary sits at x 5595 of 5595 — the file itself ends there. The dark band along that side is the album gutter falling into shadow, not a border and not damage. We did not invent paper to replace it, and we did not shift the image to hide it.
Corner losses against the sheet's true rectangle measure 0.5 / 4.8 / 1.6 / 0.5 mm. The page was bound and has not lain perfectly flat since the 1850s.
Following our standing rule for Atkins, the whole blue page is the work — the cyanotype ground is not background to be trimmed away. We crop to the leaf, not to the specimen.
What we are allowed to sell
The original. Anna Atkins died in 1871. The work is in the public domain worldwide.
The digitisation. The New York Public Library releases this image without known copyright restrictions and permits commercial use.
Our file. The crop, the tonal work and the border are ours. We sell you a print of it; we do not sell you the rights to it.
Framing this sheet
- 30 × 40 cm
- Image 21.32 × 27.00 cm, margins 4.34 cm sides / 6.05 cm top / 6.95 cm bottom
- 50 × 70 cm
- Image 42.00 × 53.20 cm, margins 4.00 cm sides / 7.82 cm top / 8.99 cm bottom
- Frame
- A standard 30 × 40 cm or 50 × 70 cm frame takes the sheet as printed, no trimming
- Passepartout
- Optional. The printed border already gives the sheet air. If you want a mount as well, go one frame size up rather than cutting into the border
- Glazing
- Cyanotype blue is what the eye goes to — museum glass or acrylic with UV filtering keeps it from greying under daylight
Measure your frame before you order. Frame sizes vary between makers, and some "50 × 70" frames have a rebate that swallows several millimetres on each side. We give the exact printed dimensions above so you can check; we cannot take responsibility for a frame that turns out not to fit.
All sheet records: museartis.com/pages/sheet-records · Questions about this sheet: info@museartis.com