I like to think she's a pretty sophisticated canine!!!
However, this means my housemates don't always know she's alone and don't know to let her out. Sooooo, I made this door tag.
I made it at Techshop! (San Francisco)
I'm also making one for my acupuncture clinic: it will say "session in progress." That's what the illustrator template says, which is attached to this instructable.
Caveat: I'm going to show you the photos of my first attempt. I realized I mis-guessed the measurement to fit on an actual doorknob. So as you can see I hung it on a nail. To avoid this use my illustrator template, which is 4.25" width by 11" height. If your cut is 4.25" wide and you make a sizable round hole at the top then it'll fit over the door knob.
I made it this size in case you want to use an 8.5x11" piece of fancy paper instead of wood. I'm going to see if I can link to my new illustrator CS3 template.
Step 1: Design in Illustrator (or whatever program you use...)
I cut a circle or oval out of the top, which will make the hole that fits over the door knob.
I selected a font I liked for the bottom, typed it, aligned it, creating outlines, making the line .001 thick so it'll cut (not etch). Please see my "baby mobile" instructable for more information about all this and into specific to the 60 watt machine at San Francisco's Techshop.