Do not mess with Stephanie Pearl-McPhee: She's got a posse of knitters, and those folks are armed with sharp, pointy sticks. Pearl-McPhee, of the blog yarnharlot.ca, has a devoted following—she regularly packs a few hundred knitters into her readings. Expect the same during this visit to Powell's, for her book Stephanie Pearl-McPhee Casts Off: The Yarn Harlot's Guide to the Land of Knitting, a sort of Lonely Planet-style guide to knit culture.

MERCURY: Everywhere you go, you ask knitters to come out of the woodwork to "represent"—and they do, by the hundreds!

PEARL-McPHEE: It's a crazy little subculture. The reason I've been doing it is because there are so many stereotypes about knitters that people can't let go of. If you're booking two decorators who've written a decorating book into a bookstore, you're having a book event, not a decorating event. And if you get a guy in who writes books about fishing, you're having a book event, not a fishing event. But as we set up these things, it's consistently referred to as a knitting event. It's like people can't get by that first part. Everything you might say about yourself as a person is negated by the stereotypes that they have about you as a knitter.

Last time you were here, you were at the smaller Powell's—and drew quite a crowd. This time, you're at the much larger Burnside location.

The first time I came to Portland I was at the big one, and I filled the joint. This is one of those things where they have a first-hand experience, they know how many people are coming, but their home and garden books are at the other location, so that's where knitting goes! Despite the fact that the knitters won't fit there. It was really crowded—it's our perpetual chair problem, where we tell them how many knitters there are, and they put out however many chairs their image of knitters is going to need.

What's the ratio of chairs to knitters?

They all screw it up in creative ways. And some of the places nail it.