What does 300 DPI mean?
DPI means dots per inch, so when referring to 300 DPI, this means 300 dots per inch. When I first started out in the design industry, I was getting many request to make sure the image I was working with was “300 DPI”, even when putting images on the web. Through my experiences, I realized the DPI resolution is more important with printing, rather than for any images you display on a website. 300 DPI is one of the most popular industry standards safe for a great print product in the end.
DPI (dots per inch) vs. PPI (pixels per inch)
Although “dots per inch” is the technical term, it may be a little easier to remember it as “(PPI) pixels per inch” at first when preparing the image to ensure it is 300 DPI. Keep in mind printers print “dots” and most applications such as Photoshop, InDesign, Illustrator, etc refer to “pixels”. So pretty much the same concept, but depends on if you are referring to the printer or application.
How to make an image 300 DPI
So you know you need to make the image 300 DPI, but you also need to know a little more information to accomplish this in the end result. You need to know how large/small the image is supposed to be printed at. You can make any image 300 DPI, whether it’s to be sized at 1” x 1” or 8” x 10”.
To figure out how to create an image that will print 300 DPI, first figure out the size you need in inches, then times each of those dimensions by 300.
Here is an example of how you would figure out how to print a 4” x 6” photo in 300 DPI:
4 inches x 300 dpi = 1200 pixels and 6 inches x 300 dpi = 1800 pixels. So in whatever software application you use, make sure the image is 1200 pixels x 1800 pixels to print an 4” x 6” image at 300 DPI.
If you need to figure out what DPI your photo is currently at to print, simply switch around the figures. So for example, you want to print another 4” x 6”, but the photo you have is only 600 pixels by 900 pixels. Here is an example of how you would figure out what the DPI is of your image:
600 pixels/4 inches = 150 dpi and 900 pixels/6 inches = 150 dpi. So as of right now, this image is only 150 dpi, which in some cases, may be acceptable for printing, again it will depend on the printer or client.
Here is my cheat sheet/list of how many pixels you need to print 300 dpi in some of the most popular sizes:
If you use a software application such as Adobe Photoshop to edit your photos, you can easily change the DPI to 300 right when you start a new document (the default is usually set at 72 DPI). Now if you are simply opening an already existing photo, there are two ways to get the 300 DPI status quickly if no specified print size:
- Once the image is opened in Photoshop, go to Image>Image Size from the menu and make sure “re-sampling” is checked and make it 300 DPI. This will automatically resize larger onscreen, and give you 300 DPI when printed. Or;
- In the same Photoshop dialog box, same steps, except uncheck “re-sampling” and it will not change the onscreen appearance, but it will shrink the print size down so it prints 300 DPI.
Sometimes this method will work, sometimes not. It will depend on the image’s pre-existing pixel dimensions and what dimensions you will need it to print.
I always make sure I have the highest resolution image in pixels I can get so I can use it for any size I want, while maintaining the quality of the image.
Do you really need 300 DPI for the Web
I would say no, worry about the dimensions you need to size the image to, usually always in pixels, which will depend on what you are doing. I do not think I have ever come across a site, such as a social media site, or even when designing a WordPress site, where it puts the dimensions needed in anything other than “pixels”. For example, the Facebook Cover Photo specifies that they need to be 851 pixels x 315 pixels. Another example with designing WordPress websites, is I usually always “Inspect the Element” for images to figure out what the dimensions needed in specific spots, or slider sizes, again always in pixels.
Remember, don’t let DPI scare you, it is a lot easier then what you read or think about it.
Recommended Online Printers
Company Folders, GotPrint.com, and UPrinting.com are printers I have worked with and enjoyed working with because of their competitive pricing, great quality, and shipping is fairly decent. They let you know what dpi or file size, and what guides you need to stay within when preparing your document for print.