US 8 straight needles.
5 oz Red Heart Super Saver yarn--yeah, I know all the other bag patterns say "cotton", but this is my book bag. I want indestructible. I used the Sunshine Print colorway.
Crochet hook, whatever size you prefer (I used a G because that's all I have).
These instructions give about a 12"x12" backpack, empty. It'll stretch quite a ways, so don't make it too big if you don't want lumbar problems.
Cast on 39 sts using long-tail cast on; purl one row. (This gives a sturdier edge.)
Row 1: *K2tog, yo; rep from * across, end k1.
Row 2 and all WS rows: purl.
Row 3: K1, *yo, k2tog; rep from * across.
Work in patt till piece measures 24" long. Use this stretchy bind-off: k1, *yo, pass k st over yo, k1, pass yo over k st; rep from * to end. Do NOT cut yarn or fasten off.
Place last loop on crochet hook. Fold piece in half, placing CO and BO edges together. Crochet side edge together; I used the following method, which produces a good stretchy edge.
*Sc in hole below CO edge. Ch 1. Sc in hole below BO edge. Ch 1. Rep from * down, alternating sides and placing 1 sc in each hole along edges, with a ch between each one. It'll look a little bulgy when the bag is empty, but believe me, you'll need the flexibility when you fill it.
When you run out of holes to single-crochet in, do NOT fasten off; ch 1, turn. Work 7 single-crochet sts back along joined edge--spreading them out more than normal is a good idea. Ch 1, turn.
Work even in single crochet over these 7 sts until strap measures about 12-14 inches. When it's long enough, fasten free end of strap to CO edge by crocheting into strap and CO edge at the same time.
Before fastening the strap, you need to be sure it's twisted the right way; it's hard to explain. Hold the backpack against your back as if you're wearing it, and make sure the strap lies (more or less) flat against your body all the way up.
Once the strap is attached, you can finally fasten off, leaving a nice longish end to weave in--remember, this critter is going to take some hard wear. You don't want the strap giving way because your fasten-off came undone.
Now join the yarn at the other top corner, on the side you haven't seamed up yet, and repeat the whole process from "Crochet side edge together", way up ⇑ there. Weave in those two ends, and you're done!
You can make an iCord drawstring if you want, especially if you'll only be carrying light loads, but you don't really need it. This is a very well-behaved backpack.
To bundle it up like this picture, with a handy loop to hang it from your bike handlebars, just fold it in half--either way, doesn't matter--then roll it up so the long edge curls around. (How am I supposed to describe this stuff? sigh...) Twist one strap around it, rather like a ponytail elastic, and the other strap forms the loop.
Copyright (insofar as a mesh bag pattern can ever be copyright) August 2008 by Maria Grace McClamrock, aka "telcontar" on Ravelry.
