The standard for beautiful A4 printing is 2480 x 3508px at 300dpi, and 3508 x 4961px for A3. If you are looking at a bulletin board from a distance, 150 to 200 dpi may be practical. Even if you enlarge the image beyond the original image, details will not increase.
Pixels and DPI have different roles
Pixel is the number of dots that make up an image, and DPI is a measure of the density of how many dots are placed in 1 inch for printing. Even if the number of pixels is the same, if you print smaller, the density will be higher, and if you print larger, the density will be lower.
300dpi is often used for home photographs and fine text. 150 to 200 dpi may be sufficient for objects viewed from a distance, such as posters.
Typical Paper Size Guidelines
The standard for 300dpi is 1748 x 2480px for A5, 2480 x 3508px for A4, and 3508 x 4961px for A3. If it's landscape, swap the portrait and landscape.
Additional coloring may be required for borderless printing or submission to a printing company. If you have a designated template, be sure to use it instead of just using the numbers that fit on the paper.
- A5：1748×2480px（300dpi）
- A4：2480×3508px（300dpi）
- A3: 3508×4961px (300dpi)
What happens if I enlarge a small image?
Even if you increase the number of pixels by resizing, it does not completely restore the original details. Outlines may become blurred or letters may smudge. Work from the largest original document possible.
Images and screenshots saved from SNS may be scaled down for display purposes. Finding the original photo or production data will yield better results than simply enlarging it.
Try it in real size, not just numbers
To make a final decision, it is best to print a portion of the image at actual size using the printer and paper you are using. Try a range that includes important parts such as faces, thin text, and QR codes, and check from viewing distance.
If the aspect ratio of the image and the paper ratio are different, decide in advance whether to crop or use margins.
Confirmation before and after resizing
- ✓Determined paper size and orientation
- ✓Determined the required DPI
- ✓Used a sufficiently large original
- ✓Maintained aspect ratio
- ✓Trial printing of important parts at actual size
Image resizing
In addition to specifying pixels, you can adjust the image size by selecting the ratio of A3, A4, or A5.
Image resizing→This article gives general guidance. If a recipient, printer or official service provides its own requirements, follow those requirements first.
A SMALL NOTE FROM SPACEEven if Jupiter is displayed larger, the pattern of Jupiter will not increase. The image is the same. A good original is a telescope that looks at distant stars.