In this post, we’re going to take a look at resolution requirements: more specifically, what they are and why they matter. Before we get to talking about image resolution requirements, however, we have to talk about image resolution itself.
What is image resolution?
Put simply, the resolution of an image is the degree of detail visible in a photographic, digital or television image. More specifically, since image resolution is typically displayed in pixels per inch (PPI), an image’s resolution is how many pixels are displayed per inch of the image.
High resolution images are images that contain more pixels per inch, meaning that they show more information and therefore create a higher-quality, crisper image.
Low resolution images, on the other hand, have fewer pixels and display less information. This means that if those few pixels become too large, such as when an image is stretched, they can become plainly visible.
How to increase image resolution
When you change the resolution of an image, you are telling the image editing program how many pixels you want to live in an image. So, for example, a 300 PPI image contains 300 pixels in each inch of the image, resulting in an image that’s crisp and detailed.
Compare that to image that’s only at 72 PPI: an image at 72 PPI won’t be nearly as crisp as one at 300 PPI or 600 PPI.
The biggest rule of thumb when it comes to image resolution is to start at the highest resolution you can and work downward. Need an image that’s 600 PPI? Start with one at 1000 PPI. It’s easier to have more information and work downward than it is to start with not nearly enough (72 PPI) and try to work upward to 300 or 600 PPI.
Image resolutions and PPI requirements
The image resolution you need (and subsequently, how many PPI you need) depends entirely on what kind of image you’re making. That is to say that image resolutions for web differ from those in print, and print requirements differ depending on what kind of surface you’re printing on.
Web images depend much more on the pixel dimensions: that is, the size of the image. However, pixels per inch and the overall image resolution also play a factor: A 300 PPI image displayed at a 300 pixel by 200 pixel size will look much better than a 72 PPI image displayed at the same size.
So, how does this differ from print? At the print scale, print size/product size and the image resolution required are pretty much synonymous – that is, as the product size increases, so too do the image resolution requirements.
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The resolutions for printing on cloth differ, too. Printing on cloth usually uses DPI (dots per inch) as opposed to PPI. DPI refers to the number of physical dots of ink on a physical item. Take a look at the infographic below to learn more:
For more information about pixel dimensions and printed image resolutions, take a look at the Adobe Support article on the topic.