For an old photograph, a careful scan is often a better starting point than a quick phone picture. A flatbed scanner can keep the print square and avoid the reflections that appear when you photograph a glossy surface.
Handle the original gently. If it is fragile, stuck to glass or fixed into an album, do not pull it free just to scan it. Preserve the physical photograph first.
Prepare the scan
Clean the scanner glass according to its instructions. Remove loose dust from around the work area, but avoid household cleaners or rubbing the photograph itself. Place the print straight on the glass and preview the whole picture before scanning.
Scan in colour even if the original looks monochrome when you want to preserve warm paper tones or a faded tint. You can make a separate black-and-white version later.
Choose resolution for the enlargement
The required scan setting depends on how much larger the new print will be. As a planning example, a 6 × 4 inch photograph scanned at 600 DPI produces approximately 3600 × 2400 pixels. At 12 × 8 inches, that provides 300 PPI; at 18 × 12 inches, it provides 200 PPI, before cropping.
This does not guarantee either size will look sharp. The original print may already contain blur, grain or limited detail. A higher scan setting records more samples; it cannot reveal information that was never present. Use the scanner’s genuine optical capability rather than assuming an interpolated setting adds useful detail.
Save an untouched master
Keep a high-quality master scan and create a separate copy for straightening, cropping or colour adjustments. Check faces at full size on screen. Dust, scratches and scanner reflections are much easier to spot before printing.
If you cannot scan the photograph, use even light and hold a camera parallel to it. Avoid flash reflections and retain the full-resolution file.
Finally, choose a canvas proportion that preserves the people and details you care about. See the photo canvas options and check the crop before committing to an enlargement.