Technical guide
How to Prepare Files for Fine Art Printing
The useful question is not “Is this image 300 dpi?” but “How many pixels does it contain at the printed image size, and what does that detail look like?” Use this guide to prepare the file, then confirm the final specification with Lumière Print.
1 · Pixels at final size
Check pixels at final printed size
Divide the size in centimetres by 2.54 to get inches, then multiply by the desired ppi. Around 300 ppi suits close-viewed detailed work; around 150 ppi can be a discussion point for large work viewed farther away. Planning benchmarks, not automatic acceptance thresholds.
| Printed image size | At 300 ppi | At 150 ppi |
|---|---|---|
| 20 × 30 cm | 2,362 × 3,543 | 1,181 × 1,772 |
| 30 × 45 cm | 3,543 × 5,315 | 1,772 × 2,657 |
| 40 × 60 cm | 4,724 × 7,087 | 2,362 × 3,543 |
| 50 × 70 cm | 5,906 × 8,268 | 2,953 × 4,134 |
| 60 × 90 cm | 7,087 × 10,630 | 3,543 × 5,315 |
| 100 × 150 cm | 11,811 × 17,717 | 5,906 × 8,858 |
A larger paper sheet around the image does not increase the pixels required for the image itself.
2 · Genuine detail
Preserve genuine detail
Changing the resolution field from 72 to 300 without changing pixel dimensions does not create detail. Upsampling can change the appearance of an image, but it cannot recreate information that was never captured.
If the source is limited, tell the studio the final viewing distance. A smaller image area, different crop or a deliberate soft look may be more appropriate than aggressive enlargement.
- Examine the file at 100% for focus and motion blur.
- Look for compression blocks and heavy noise reduction.
- Check sharpening halos along edges.
3 · Format
Choose a practical format
Format guidance, not a published upload policy. Ask the studio about accepted file types, transfer method and maximum size.
| Format | Useful for | What to watch |
|---|---|---|
| TIFF | High-quality flattened photographic or artwork master | Larger file size; embed the correct profile |
| High-quality JPEG | Convenient final export of a photograph or raster artwork | Avoid repeated re-saving or heavy compression |
| PSD | Layered editing file when specifically requested | Confirm whether the studio wants a flattened copy |
| PDF / vector | Graphic art or line work | Confirm fonts, transparencies and output workflow |
4 · Colour
Keep colour information attached
Export an RGB file with its ICC profile embedded, for example sRGB or Adobe RGB when that is your actual working space. Do not assign a different profile merely to make colour appear brighter. Avoid an unrequested CMYK conversion.
If you soft proof, use the output profile and rendering settings the studio confirms for the specific printer, ink and paper. A profile for a different device or medium can mislead.
5 · Image vs paper
Separate image area from paper size
Write down the printed image width × height and the desired outer sheet width × height. A 30 × 45 cm image with a 2.5 cm white border on every side needs a 35 × 50 cm sheet. No default border is promised, so request the border explicitly and confirm its price.
A 2:3 file fits 30 × 45 cm without cropping, but not 50 × 70 cm (5:7) if you fill the entire rectangle. Mark any subject matter near the edge that must be kept.
Before you send
Final file and order checklist
- Use the final edited master, not a preview or social-media download.
- Keep the original uncropped version separately.
- Check pixel dimensions and sharpness at intended size.
- Embed the correct RGB ICC profile.
- Specify image size, sheet size, crop and border.
- Name each file clearly and list quantities for a series.
- Tell the studio about critical colours, prior reference prints or intended display light.
Keep reading
Sizes, crops & borders
Image area, sheet, frame and crop.
Colour & soft proofing
ICC profiles, darker prints and soft proofing.
Photographing artwork
Light, alignment and colour for a master file.