Calligraphers are always on the lookout for cool studio tools and guideline makers. Hanging out on social media can net you some great resources; online guidelines generators are some of these.
These are good, but give me one of those green lettering liners any day. Too bad they’re not made anymore. The closest equivalent is the Ames lettering guide, but I don’t use those. It took me awhile to figure out what was wrong with them. There just aren’t enough of the holes that I use for pencil guidelines. The Linex (Koh-i-noor and Steadtler also made them) liner, on the left below, has 16 holes, compared to the Ames lettering guide on the right, which has only 10 holes down the center. The Linex lets you do a lot less repositioning, which means you can do it in a lot less time.
These lettering liners are far from intuitive. There’s a great tutorial at JetPens that explain how to use all the features of the Ames lettering guide. I only use the center row; the holes in that row are equidistant. But perhaps I should try the other rows, which allow for an x-height that 2/3 of the capital height, or an x-height that is 2/3 the capital height.
Guidelines are a constant source of interest to calligraphers. I’m amused to re-read my post on guidelines from more than 10 years ago on the subject. I still mourn the demise of Calli-Graphic, an app that allowed one to make straight and even circular guidelines with a desired x-height and leading.