Print guide
How to print your star map so it looks right.
Your file is 9,000 px wide: a true 300 dpi even at the largest size. Below: every size and its pixels, which material to pick, and where to order.
Sizes and resolution
You do not need to think about pixels. Your file is sharp at every size up to 30×40 in (75×100 cm). Pick the size that suits the wall, and tell the print shop that size.
Small
8×10 to 12×16 in · A4, A3, 30×40 cm
A desk, a shelf, a bedside table, or a gift that is opened by hand.
Medium
18×24 in · A2, 45×60 or 50×70 cm
Above a bed, a desk or a dresser. The size most people choose.
Large
24×32 to 30×40 in · A1, 60×80 or 75×100 cm
Above the sofa or as the one piece on a big wall.
Your poster keeps the shape you chose
- Portrait 3:4 fits frames like 12×16, 18×24 and 30×40 in, or 30×40 and 60×80 cm.
- Tall 5:7 fits A4, A3, A2, A1 and 50×70 cm, the usual European frames.
- Square fits square frames: 12×12, 20×20 in or 30×30, 50×50 cm.
Have a frame already? Choose the matching shape in the studio before you order, and the print fills it exactly.
What to tell the print shop
“Please print this file at 18×24 in on matte paper, scaled to fit, with no cropping. It is a 300 dpi file.”
Change the size and paper to yours. “Scaled to fit, no cropping” keeps the border and the names exactly where they are.
Exact sizes and pixels, for print shops
Portrait 3:4 — the classic
| Size | Metric | Pixels at 300 dpi |
|---|---|---|
| 9×12 in | 23×30 cm | 2,700 × 3,600 |
| 12×16 in | 30×40 cm | 3,600 × 4,800 |
| 18×24 in | 45×60 cm | 5,400 × 7,200 |
| 24×32 in | 60×80 cm | 7,200 × 9,600 |
| 30×40 in | 75×100 cm | 9,000 × 12,000 |
Tall 5:7 — also fits the A-series
| Size | Metric | Pixels at 300 dpi |
|---|---|---|
| 5×7 in | A5 / 13×18 cm | 1,500 × 2,100 |
| A4 | 21×29.7 cm | 2,481 × 3,507 |
| A3 | 29.7×42 cm | 3,507 × 4,962 |
| A2 | 42×59.4 cm | 4,962 × 7,017 |
| A1 | 59.4×84.1 cm | 7,017 × 9,933 |
| A0 | 84.1×118.9 cm | 9,933 × 14,043 |
Square 1:1
| Size | Metric | Pixels at 300 dpi |
|---|---|---|
| 12×12 in | 30×30 cm | 3,600 × 3,600 |
| 20×20 in | 50×50 cm | 6,000 × 6,000 |
| 30×30 in | 75×75 cm | 9,000 × 9,000 |
Papers and materials
Fine-art matte paper
Our first choice. 200–310 gsm, cotton or alpha-cellulose. Deep blacks, no glare, the stars stay crisp. Ask for “giclée” or “archival matte”.
Satin or lustre photo paper
A soft sheen that makes dark papers look richer. Frame it behind glass; it shows fingerprints if handled.
Canvas
Warm and gallery-like. Choose a “mirror” or coloured edge so the border is not wrapped round the sides, or order a size larger.
Metal (aluminium, dibond)
Modern and very sharp. White-base aluminium keeps the paper colours true; a brushed finish suits Black and Midnight.
Acrylic glass
Face-mounted acrylic gives depth and a gloss like still water. Spectacular in large sizes, heavier on the wall.
Wood
Printed on birch or maple, the grain shows through light papers such as Ivory. Best kept to small and medium sizes.
Where to print
A local print or copy shop
Quick and cheap for posters up to A2 or 18×24 in. Bring the file on a USB stick or send it by email.
A photo lab or giclée studio
The best colour and paper choice, especially for dark papers and large sizes. Many also frame.
An online print service
Upload the PNG, choose size and material, and the print arrives framed or ready to hang. Choose the exact size from the table above.
At home
Choose “actual size” or “100%” in the print dialog, and the heaviest matte paper your printer accepts.
Tips for a perfect print
- 1Order the file at the size you will print, or the next size up — never stretch a small file to a large print.
- 2Ask the printer to switch off “auto-enhance” or “auto colour”. Dark papers are designed dark on purpose.
- 3For a large or costly print, order a small proof first. It costs little and shows how that printer handles deep navy and black.
- 4Home printers are fine up to A4 or Letter. For anything larger, a print shop or online lab gives far better blacks.
- 5In a frame with a mat, order the print 2 in (5 cm) smaller than the frame opening, or ask the framer to cut the mat to your size.