To find the pattern, click through to the Chain Reaction Afghan Project page, from the ‘published in’ field, and download the free pdf there.

Finished size about 62” × 50”

Yarn: Washable worsted-weight yarn

NOTE: Yardage estimate may be high, since it was compiled from each individual afghan square.
(A) Blue 732 yd [669m] (B) Cream 999 yd [913m] (C) Green 1266 yd [1158m] (D) Orange 814 yd [744m] (E) Purple 1108 yd [1013m] (F) Red 594 yd [543m]

Edging: 1 skein each (about 200 yd 83 m): red (F), blue (A), green (C), orange (D), purple (E),

Hook: H/8 (5 mm). Adjust hook size if necessary to obtain correct gauge.

Notions: Yarn needle.

Gauge 12 sc = 4”. NOTE: Gauge can vary in each square

Note: These were separate squares published Interweave Crochet in the Summer, Fall and Winter 2010 and Spring 2011 issues, but they were also published in their entirety as a single afghan in a free booklet available from Interweave’s Crochet Me Chain Reaction Afghan Website.

There are a number of designers for the project, all credited in the PDF.

Here are the notes from that site:

Welcome to the Chain Reaction Afghan Project, a yearlong celebration of collaboration! We are creating an afghan made up of squares created by your favorite crochet designers, combined with squares designed by you! We’ve publish 10 patterns by designers, 5 each in the Interweave Crochet Summer 2010 and Fall 2010 issues. The top ten Readers’ Choice squares will be published with their patterns in the Interweave Crochet Winter 2010 and Spring 2011 issues. You can see our contest rules page for more information. The whole afghan will be assembled and shown in the Summer 2011 issue, before the afghan is auctioned for charity.

Chain Reaction Afghan but our afghan is just the start of the Chain Reaction. You can carry it forward by making your own afghans for donation. For every afghan you donate, alone or as a group, we will donate $5 to Warm Up America (for up to a total of 500 afghans). Every afghan must feature squares from the Chain Reaction Afghan Project. All other choices are your own: the yarn, the number of people who participate, the size of the afghan. When you are done, send an email to us that includes a picture of the afghan, the name of the group you donated it to and why, and information about the crocheters who made the afghan. Please put Chain Reaction Afghan Project in the subject line and send to crochet@interweave.com.

Now, those twenty square designs have been collected together into one eBook! Plus, you will get the instructions for creating the final afghan. If you choose to make the afghan from the magazines you will need all the listed issues.

Video instruction is available for purchase as well, either as a DVD or a video download.

Summer 2011 issue has joining directions and instructions for the edging, which is also included in the ebook.