What Resolution Should My Print File Be?
The answer to this question is often misunderstood because it hasn't been defined well for print buying customers. We'll start our answer by addressing the quality of images you want to print and a clarification of terms.
Your image(s) should be the highest quality and size you can provide. The bigger the better. Why? Because when you scale an image to be larger than its original size image quality can be lost. This does not occur when making an image smaller than it's original size.
To better understand image quality we need to be on the same page when using often mis-used or wrongly defined terms:
- DPI (Dots Per Inch): This is the number of linear dots that are printed per inch. Simply put, the higher the dpi the higher the quality of the final print piece. Compare the DPI of a comic book or newspaper to a magazine like Vogue and you can literally see the diffence.
- PPI (Pixels Per Inch): This typically applies to images or pixel density on the screen of electronic devices (TV's, computer monitors, smartphones, tablets, etc...), but in the printing industry this usually defines the pixel density of an image in a print file.
- Resolution: Simply put, this is the measurement used to define how the image is displayed by width and height. For example, most small computer montior resolutions are 1024 x 768. Meaning it displays 1024 pixels horizontally and 780 pixels vertically.
When buying a TV you want more pixels because the resolution is better. However, don't confuse resolution with size because it simply isn't always true.
The Root of the Confusion
The terms above are used by the print providers and web designers. While they mean the same to both industries the end results are completely different. Here's the breakdown. The confusion comes from applying the terms dpi and ppi to the incorrect output medium.
- Printing Industry: 300 dpi is the standard all print providers desire. You can defintely go higher because, as mentioned, higher is better. As for a minimum we ask our customers to stray away from using images lower than 150dpi. We do understand customers may not be able to provide a higher resolution image than 72dpi. We just want print buying customers to understand why the quality of a printed 72dpi image does not match what you will see on your computer screen or other electronic device when scaled to be larger than it's original size.
- Web Design & Digital Industry: Typically images on the web are 72dpi. This is a standard of their industry and applies to websites, monitors, and other electronic devices. We recognize the fact that a lot of Web and Digital designers use images over 150dpi.
Electronic devices all have different resolutions and, therefore, display images a little differently. For example, using a 72dpi image on a monitor set to 1024 x 768 resolution will display the image at roughly 70ppi. Likewise, if the resolution of the same monitor is set to 1280 x 1024 it will display the 72dpi image at roughly 85ppi. Sure, you'll get more detail, but note how everthing is now smaller.
Photo byrawpixel on Unsplash
It's easy to confuse file size with image size. Image size is only defined by the dimensions of the image. The file size is defined by kilobyte, megabytes, and gigabytes; which is how much space it will occupy on your storage device. Generally speaking, high quality image (300dpi or higher) will result in a file size. Whereas, the same image of lower quality (150dpi or smaller) will be a smaller file size.
TL/DR (Too Long / Didn't Read)
If using images from the web, make sure they're the highest resolution you can provide. The more ppi you can provide, the better. If there are too few pixels per inch, then the pixels will be large and very pixilated (jagged edges, which makes for rough edged, sometimes blurry images).
If you're creating an image from scratch the image quality should be 300dpi or higher.