We recently received an excellent question from one of our customers about photo resolution and how it relates to enlarging photos for printing on canvas, metal or photo paper vs displaying on a website. Caroline did such a wonderful job answering the question I thought it would be great to share on the blog.
Q - "I had a question for you regarding the printing format for photographs. Should my resolution be at 300 dpi and just shrink down the dimensions for a smaller file size? I have been sending in files with a resolution at 72 dpi and they seem to be printing out fine.
Is this "rule" something to do with printing photos for brochures or ads?" - From P.W
A - In general, we don’t worry about the dpi a file is set at, we are more interested in the total pixel dimensions. The best thing is to just take the images at the highest quality setting allowed by the camera, and leave the files at that size as well. For example, your picture is 4736x3156 pixels. This displays as 65.778" x 43.833" at 72 dpi, OR 15.787" x 10.52" at 300 dpi. Either way, it’s great quality as you’ve seen from the prints.
Some people do manually resize their images, for example changing this one to 30" x 20" at 300 dpi, but I generally don’t recommend that. It’s often MORE than is needed so you’ve unnecessarily resampled it and are not maintaining the maximum amount of sharpness and clarity. For example, we don’t even print at 300, photos on canvas are printed at 180 dpi and metal + photo papers are printed at 240 dpi. My rule of thumb is as long as the actual pixel dimensions are about 2000 and higher, it’s perfectly fine and can be formatted by the printer for optimal results.
When it comes to brochures/ postcards, etc I would probably say it’s about the same however you can usually request a template or file specs from the print company and that will let you format it precisely. They may have restrictions on images being too big, in the case of this example photo it’s way larger than needed for a postcard in it’s natural form so they may require it come down in size a bit.
One thing I can say is DEFINITELY required for resizing is when prepping them for web. You probably already know and do this but I’ll explain my process: I never upload anything online that is larger than 1200 pixels and depending on the use, I often do smaller than that. For example, I’d resize the sea oats to be 14" wide at 72 dpi and that makes the pixels 1008x672. Save as a new filename with "web" or something in it because this file will now no longer be possible to make prints at all (for example if you file name was- sample_100.jpg you would rename it to sample_100web.jpg. That’s what I would then upload to your website, because not only will it take less time and always load fast when being viewed online, it prevents theft of the image as people won’t be able to make their own nice big print of it from such a small file.
If you ever have any doubt about the resolution or quality of the photo you want to print on canvas, metal or photo paper please don't hesitate to contact us or use our free image consultation.