Tricked my own eyes by squinting at my poster design, and it actually worked
I was stuck on a coffee shop poster last week because the headline kept blending into the background even though my contrast checker said it passed. On a whim I leaned back and squinted until the whole thing turned into blurry blobs, and the headline vanished while the body text stayed readable. I bumped the headline from a 60 percent gray to near black and lightened the photo behind it, and the squint test suddenly showed the words popping right out. Took maybe 10 minutes total after two hours of color picker fiddling. Does anyone else do the blur or squint thing on real jobs, or is there a better way to catch this before printing?
Squinting is the oldest trick in the book and it still beats half the tools out there, since it strips away color and just shows you value. I do the same thing with the blur filter in Photoshop when I'm not near a printer, and nine times out of ten the thing that fails the squint test is the thing that would've failed on paper. Your contrast checker only measures the numbers, not how the eye actually reads the page, so trust your squint over the software.