Dave Renfroe
Active Member
I ran across some 4x6 double sided photo paper and said ..... hmmmm.
I wonder if I did the math, could I come up with a print on both sides of the paper that match exactly to make a custom book-mark? ....... yes!
A few years ago I was so confused about the dreaded DPI setting when I was trying to create a print to mount on an odd shaped panel I made. So I experimented and got it. The printer makes good use of DPI setting in determining the size of the printed image.
I was so thrilled that I made a YouTube video in an attempt to explain the relationship between DPI, PPI, image size and what size ends up on the paper. The video is a bit long, but I got into explaining the math around the aspect ratio as well. Here is the link:
So for my bookmark idea, I just took my desired dimensions of the bookmark and calculated my DPI setting and set that in the Resize dialog in Affinty photo. I wanted 2 images of the same size on the front and back of the paper. I found that once I set the correct DPI for the 5.5" length I wanted - the printer just puts it right in the middle of whatever paper size you chose and puts it in the exact same spot when you turn the paper over. Please see my math on the attached photo. (Both photo images are on the same piece of paper.)
Note: - You need to un-click "resample" in Affinity Photo and all it does is change that number in the metadata - it does nothing to the quality or pixel size of the image.
BTW - another "myth" I hung onto (besides DPI is irrelevant) was that 300dpi is the magic number and your printer can not produce anything better if it is higher - not true.
I hope this helps some folks out there.
