The What, When and Why of Digital Image Resolution

Whether you are a graphic designer, a small business owner, or even just a customer, you’ve likely heard terms such as “image resolution” and “DPI” when discussing logo concepts, ad development, or anything else related to graphic design. You know, or are told, that such terms are very important, but if you don’t understand what they mean or why they matter, it can hinder not only your ability to work with a client or a designer, but also the success of your ad campaign and other business goals.

What is Image Resolution?

Image resolution refers to the number of pixels per inch in a digital graphic (PPI), or the number of dots per inch (DPI) in a printed graphic. Essentially, PPI and DPI are the same, but one term is used in reference to digital artwork (pixels, like the pixels on a computer screen), and the other is used in reference to printed artwork (dots, because printing utilizes “dots” of ink). If you get down into the nitty-gritty, yes, there are differences, but in the practical world of design there is no significant difference between the two.

When and Why to Use the Different DPIs

In the early days of web development, especially during the days of dial-up internet connections, it was common practice for web designers to use only 72DPI images on their websites. There were a few reasons for this:

  1. Most monitors could only display 72DPI, so using anything of a higher DPI was pointless
  2. 72DPI images took less time to upload to the servers
  3. 72DPI images also took less time to download to the end-user’s computer screen

Now, with the advancement of technology, there are monitors that can display higher resolutions. That being said, if you are designing artwork or managing photos that will be used on the web, 72DPI is still your best bet. This will ensure the fastest load time and, in an increasingly impatient world, any website that takes longer than 2 seconds to load is at risk of losing its viewers.

When designing for large format print production, your first instinct might be to find the highest-quality photo or design piece possible. You might insist that your client provide you with a 300DPI image, but in fact, this is often quite unnecessary. In fact, you are likely to be able to get away with something as low as 100DPI for large format work for the following reasons:

  1. The majority of large format products are meant to be viewed from great distances–meaning the physical spaces between the dots are less noticeable and that lower resolution is acceptable.
  2. When you are creating billboards or similarly-sized pieces, including a 300DPI image in your file is likely to increase that file size into the realm of GIGABYTES–something you want to avoid since even Photoshop and Illustrator are unable to save files larger than 2GB.

The best time to use a 300DPI image is for photographic printing or smaller works such as business cards, direct mail pieces, rack cards, or brochures. This is because they are viewed up close and should therefore display as many details as possible.


Did this article help you? Be sure to follow our blog and like us on Facebook for more posts like these!

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s