How inkjet printing works, and why you should care

I don’t normally write basic tutorials for this blog, but this topic comes up so much that I’d like to write it down in one place so that I can refer people to it. If you already know all this stuff, and if you’re a regular reader of my blog you probably do, I apologize. I’m also going to skip over some of the exceptions and details, for which I also ask your indulgence. Inkjet printers are at their heart binary devices. They can either put a dot of ink down in one of the addressable locations on the paper, or not. Some inkjet printers can also choose between two or three size ink drops, but in all cases, the drop is either spit out (that’s a technical term) at the target location or not. The kinds of images that you create on your computer are contone images. Each addressable location – call it a pixel – can take on many different values, usually 256^3 (about 16 million) or about 32000^3 (way more values). The resolution of a contone image, prescribed by the metadata for that image,…