My 300dpi file printed like a blurry mess at the shop
I designed this poster for a client's garage sale last month. I saved it at 300dpi in Photoshop, checked all the boxes, felt good about it. But when the print shop guy handed me the proof, it looked like someone smeared Vaseline on the text. Turns out I had accidentally resized the image to 72dpi when I was cropping it. Learned to double check the export settings before I hit save.