Sharp prints need about 300 pixels per inch. Upscale until your image has enough pixels for the size you want.
Print sharpness depends on pixels per inch. For close viewing, 300 PPI is the standard: an A4 (8.3×11.7 in) print needs about 2480×3508 pixels. Posters viewed from a distance can go lower, around 150 PPI.
If your image falls short, AI upscaling adds the pixels with real reconstructed detail — far better than the printer's own interpolation.
Work out the pixels needed: Multiply print inches by 300. 8×10 in = 2400×3000 px; A3 = 3508×4961 px.
Upscale: 2x or 4K output depending on how far you need to go.
Send to print: Export as PNG or high-quality JPG; set DPI in your layout software.
Real detail, not blur: Printers' interpolation softens; AI reconstructs edges.
Great for POD: Print-on-demand platforms often require 4500px+ files.
Keep transparency: Transparent PNG designs stay transparent for t-shirt printing.
Does changing DPI in metadata make an image print better? No. DPI metadata only tells software the intended size; you need more actual pixels for a sharper print.
How big can I print a phone photo? A 12MP phone photo (4000×3000) prints sharply at about 13×10 in at 300 PPI; upscaling 2x allows roughly double that.
What resolution does Printful/Redbubble want? Many POD services recommend 150–300 DPI at print size, often meaning 4500×5400 px for shirts.
Is it free to try? Yes. Signed-in accounts get 10 free credits every day, and new users can try Pro free for 7 days — cancel anytime. No watermark on any plan.