300 dpi vs 72 dpi: Understanding image resolution for print and digital

Have your images ever looked blurry, grainy or pixelated when you printed them? Do you know why? 

When I work on print materials such as brochures and postcards, image quality is crucial. I use images of at least 300 dpi to produce high quality printed materials. If you have ever printed images with the same resolution that has been used for your website or under 300 dpi, you will find a reduction in the image quality. 

Dpi stands for “dots per inch”. When an image is produced, dpi describes the dot density. Your computer monitor displays images at a web resolution of 72 dpi that looks totally fine on the screen. On the other hand, a print resolution of 300 dpi means that you need to use an image of at least 300 dpi. Do you see the difference?

300 dpi for print / 72 dpi for digital

For print example: The postcard below is 7 inches wide x 5 inches high.

Botanical-Postcard-Flyer_B_front.jpg

In the Image Size dialog box in Photoshop, the DPI is shown next to “Resolution” as 300 pixels/inch. Make sure not to enlarge the image otherwise the larger you make it, the more quality you will lose. 

Going to Image > Image Size

Screen Shot 2018-03-09 at 1.15.44 PM.png

For digital example: The Digital banner below is 1200 pixels wide x 628 pixels high.

1200x628_04_FB.jpg

In the Image Size dialog box in Photoshop, the DPI is shown next to “Resolution” as 72 pixels/inch. Again, make sure not to enlarge the image otherwise the larger you make it, the more quality you will lose. 

Going to Image > Image Size

Screen Shot 2018-03-09 at 2.37.58 PM.png

So, how do you convert 72 dpi to 300 dpi in Photoshop when you want to use an image for print? Or how do you know that an image is large enough to use for print? You need to change the size of an image without changing the number of pixels. This is how I usually do.

1. Turn off "Resample"*  

2. Change from 72 to 300 Pixels/Inch

Do you see the dimension changed on the right of the example?  This is the maximum size of the image that you can use for print. If you want to enlarge the image, you will lose image quality as I mentioned earlier. 

*Resample is changing the number of pixels. When you turn on "Resample" and enlarge an image, you will lose image quality. 

Thank you for checking out this article! Is there anything that is still confusing you? Do you have any questions? Do you want us to create print materials for you? Please feel free to contact us.