What image size should I use for a small print if the printer wants 300 DPI?
Asked 11/9/2010
7 views
2 answers
0
I have a photo that is 4000×3000 pixels. GIMP shows it as 72 DPI, but I was told the printer works best with images prepared at 300 DPI.
I want the printed image to be very small: about 3.32 cm wide (roughly 1.31 inches). How do I work out the correct pixel dimensions and resolution setting so it prints at the best quality?
For example, should I resize it to about 393 pixels wide (1.31 × 300) and set the image to 300 DPI?
Originally by Photography Stack Exchange contributor. Source · Licensed CC BY-SA 4.0
Photography Stack Exchange contributor
15y ago
2 Answers
13
When it comes to print, terms like DPI, resolution, PPI, etc. get thrown around without much care or concern as to what they truly mean. So, before I send you off to a more in-depth answer about DPI, PPI, resolution, and print, a quick summary:
- DPI: Dots Per Inch
- A 'dot' is a single element of a pixel
- On a computer screen, a dot is a single 'sub-pixel' element, and may be red, green, or blue
- On a print, a dot is a single droplet of ink expelled by the print head
- PPI: Pixels Per Inch
- A 'pixel' is the smallest element of an image, "PIcture ELement"
- On a computer screen, every pixel is composed of three 'dots' or sub-pixels, one red, one green, one blue
- On an ink jet print, every pixel is composed of numerous dots of varying ink colors, usually a mix of cyan, magenta, yellow, and black, although modern printers often have several other inks as well
- On a dye sublimation print, every pixel is a single dot from a blend of varying in colors, such as cyan, magenta, yellow, and black.
- Resolution: Variable meaning
- Regarding an image, the resolution usually means the width and height of an image in pixels
- Regarding a print, the resolution usually means the number of pixels in an inch (or cm, if you are from a country that uses metric.)
- Regarding a computer screen, resolution usually means the width and height of the screen in pixels, but can also mean pixels per inch (i.e. 72ppi is the common "resolution" of the average LCD screen, while higher end screens often have a resolution of 100ppi.)
To answer the rest of your question, I've written up an extensive article here on Photo-SE that answers that question in great detail:
Originally by user124. Source · Licensed CC BY-SA 4.0
user124
15y ago
0
Generated from our catalog & community — verify before relying on it.
Yes — for a print width of about 3.32 cm (1.31 in), 300 pixels per inch works out to about 393 pixels wide, so your calculation is essentially right.
The key point is that printers care about how many image pixels are available for the printed size. “72 DPI” in the file is often just metadata and does not mean the image is low quality. Your original 4000×3000 image already has far more than enough pixels for such a tiny print.
At 1.31 inches wide, a 4000-pixel-wide image would print at far above 300 PPI if the software keeps all pixels. So you do not need to worry about lacking detail.
If you want to prepare the file explicitly for that print size, you can set the physical width to 3.32 cm and the resolution to 300 PPI, which gives about 393 pixels wide. Many image editors can do this directly by entering print size and resolution.
In short: your math is correct, and the original image already contains more than enough data for maximum quality at that small size.
Recommended products
UniqueBot
AI15y ago
Your Answer
Related Questions
What pixel dimensions do I need for a 32×18 inch poster at 300 dpi, and which file format is best?
Should I resize a RAW product photo to the client's final 9000×6000 requirement before editing?
Should I set all delivered JPEGs to 300 dpi for printing?
What resolution do I need for a 24×36-inch photo on a vinyl banner, and does changing DPI in software help?
What happens if my image doesn’t have enough pixels for the print size I want?