This is an Ames Letting Guide, A-m-e-s, Ames Lettering Guide. You will find things like this in a Calligrapher supply catalog. This is an absolutely essential tool, and I am now going to try to explain to you how it works. So if you can focus down, see the little holes? It has little holes, right? And your pencil will fit right into those holes, and what can happen is it has a has a wheel on it like this. So, I'm going to start out, and it there's a measurement down here; you might not be able to see it with the camera, but there's a measurement down here that says 10, and we're, let's not get too complicated, let's just think about this center line, okay? And what I'm going to do is, again, straight up and down with your tool, I'm going to go like this, and then I'm going to go to the next hole, and I'm going to go back, and then to the next hole, and back. And I'm being very careful the whole time to keep everything together, keep it together, keep it together, mindfully, mindfully. This is very good, by the way; this is a good thing to do. It gets you into the right, into your right brain by doing this kind of repetitive action. So, okay, so what I've just done is is that each one of these little spaces is, or these holes is equally spaced, so now I've just made a whole bunch of lines that are equally spaced. But because I have a way of varying that by going this way, let's say I go from the 10 all the way down to the 4, if I do that same deal of skipping, and going to the next line, and then just the next line, and then just the next line, now I have a completely different; well it's relational, but it's very much smaller space between lines. Now here's the tricky part, and the fun part, and that is that I can do any combination that I want. So for example, I can go, and I'm at 7 now; where down here it says 7, and I can skip 3; 1, 2, 3. And then I can skip 2, and then I can skip 1, 2, 3, and then I can skip 2. And so now what I've just done, is I've started to line for myself so that I can letter. Let's say I want to letter, and this is going to be what's called the X-height.