PRINT GUIDE · SCANNING
How to scan old photos for printing
Scanning a family print or negative is the only way to reprint it, enlarge it or share it. The settings that matter are few: the scan resolution, the file format, and keeping dust out. Here's how to choose them for the size you want to print.
Choose the scan resolution from the print you want
Scanner resolution is measured in dots per inch (DPI) of the original. The rule is simple: scan DPI ÷ 300 = how many times larger you can print at 300 PPI. A 4 × 6 print scanned at 300 DPI reprints at 4 × 6. Scanned at 600 DPI, it has enough pixels for an 8 × 12.
| Original print | 300 DPI | 600 DPI | 1200 DPI |
|---|---|---|---|
| 4 × 6 in | 1,200 × 1,800 px prints 4 × 6 | 2,400 × 3,600 px prints 8 × 12 | 4,800 × 7,200 px prints 16 × 24 |
| 5 × 7 in | 1,500 × 2,100 px prints 5 × 7 | 3,000 × 4,200 px prints 10 × 14 | 6,000 × 8,400 px prints 20 × 28 |
| 8 × 10 in | 2,400 × 3,000 px prints 8 × 10 | 4,800 × 6,000 px prints 16 × 20 | 9,600 × 12,000 px prints 32 × 40 |
Pixels = inches × DPI. Print sizes are at 300 PPI; at 150 PPI each one doubles.
For most people, 600 DPI is the sweet spot for prints: it allows a same-size reprint with room to crop, or a moderate enlargement. Going much higher makes huge files without much extra detail, because an old print only holds so much. Small prints you want to enlarge a lot, such as wallet-size school photos, are the exception: scan those at 1200 DPI.
Negatives and slides need much higher numbers
A 35 mm negative or slide is only 36 × 24 mm, about 1.4 × 0.9 inches, so it needs a far higher scan resolution to give a useful file.
| Scan resolution | Pixels | Prints at 300 PPI |
|---|---|---|
| 2,400 DPI | 3,402 × 2,268 | about 11 × 7.5 in |
| 3,200 DPI | 4,535 × 3,024 | about 15 × 10 in |
| 4,000 DPI | 5,669 × 3,780 | about 19 × 12.5 in |
36 mm = 1.42 in; 24 mm = 0.94 in. Figures rounded.
Film scanning needs a scanner with a backlight or film adapter. A flatbed scanning a negative like a print only sees a dark, reversed image.
Scanner settings that matter
- Colour mode: scan in colour even for black-and-white prints. It captures the warm or faded tones, and you can convert to black and white later.
- File format: save the master scan as TIFF or PNG, which don't lose detail, or as a JPEG at maximum quality if space matters. Make smaller copies for sharing from the master, not by re-saving it.
- Turn off heavy auto-fixes: automatic sharpening, descreening and dust removal can help, but strong settings smear detail you can't get back. Keep the master scan close to the original and edit copies.
- Scan the whole print: include a little of the border so nothing is cropped by the scanner's auto-detect. Crop later.
Dust is the biggest time-waster.
Wipe the scanner glass with a dry microfibre cloth before every session, and handle prints by their edges. A speck that's invisible on the glass becomes a white blob on an enlargement, and removing them afterwards takes far longer than preventing them.
What about scanning with a phone?
A phone camera is fine for sharing old photos on screen, and good scanning apps reduce glare by combining several shots. For prints, especially enlargements, a flatbed scanner usually wins: even lighting, no lens distortion, no glare from glossy surfaces, and a known resolution. If you use a phone, shoot in even daylight, hold the phone parallel to the print, and avoid glossy reflections from overhead lights.
Before you print the scan
- Crop to the shape of the print size you'll order. How print shapes crop a photo.
- Check the PPI at that size. Pixels needed for each print size.
- Export an sRGB JPEG for the lab. How to prepare a photo for a print lab.
Name and date your scans
Scans carry the date you scanned them, not the date the photo was taken. Put the year and the people or place in the filename, such as 1987-beach-grandparents.tif, so the collection stays searchable. If you'll share scans publicly, remember that filenames travel with the file.
Check a scan's print size
Print Size Check reads your scan's pixel size in your browser and shows the PPI and crop at any print size, so you can confirm a scan before ordering. Your file isn't uploaded.
Check a scan's print sizeIndependent general guidance by Tidy, not affiliated with any scanner maker. Figures are calculated as shown. Checked 22 October 2026.