Zap a self-replicatingwindow stickerwith your QR reader, and you will link to a jpeg image that contains: 1, the layout of the sticker; 2, simple DIY instructions around the margin; and 3, the same QR code you just zapped. Self-replication allows stickers to disseminate through the world without money or physical transport via the energy of people who wish to spread the same message. Getting a jpeg image to contain a QR code that links to itself involves a bit of legerdemain: this instruct able will be your guide.

Step 1: Design Your Sticker

Use a page layout program to design your self-replicating sticker. You are welcome to use one of my modifiable Pages files on www.stickerdujour.blogspot.com as a starting point for your own self-replicating sticker. Include a white square in your design: that will eventually hold the QR code.

Step 2: Make a Dummy Blog Post

Make a blog post on a hosting service that allows you to edit a post after publication. Include a title that quotes the text of the sticker, and a line in the body saying, "Print on ordinary paper and follow the instructions in the image." That should be enough (no picture of the sticker is included at this point) You might also want to include a link to a site associated with the cause.

Step 3: Publish the Blog Post

Publish the dummy blog post. Now view it and copy the URL that appears in the address bar of your browser.

Step 4: Generate the QR Code

Paste that URL in a static QR code generator. It will generate a small image containing the QR code.

Step 5: Drag the QR Code Into Your Design

Drag the QR code image into your desktop publishing program (you may need to the image's properties to "floating" and "does not cause wrap,") and then scale it to fit inside the white square.

Step 6: Save Your Design As a PDF

Save your sticker design as a PDF, on a Mac that's: Print: Save as PDF.

Step 7: Open Your PDF and Export As a Jpeg.

Use a PDF-viewer that can export pages as jpegs. On a Mac use Preview: Export: JPEG: High Quality: 150 dpi. That will give an image 1650 pixels x 1275 pixels—that's plenty sharp enough for this purpose.

Step 8: Upload Your Jpeg to an Image Sharing Site

Upload your jpeg to a sharing-friendly image hosting site. Copy the image URL (the Direct Link) that the site provides.

Step 9: Edit Your Blog Post

Edit your previously published blog post. At the top insert an image from a URL, pasting in the URL you copied from your image hosting site.

Step 10: You're Done!

You're done. Now anyone scanning your sticker will link via your blog post to an image containing everything they need to make their own sticker—and their sticker will also be self-replicating. To make your own physical sticker, follow the instructions in the image: print on ordinary paper, coat the front of the sticker thoroughly with lip balm (all the way out to the edges), trim along the dotted line, press the sticker thoroughly against the inside of a window in a location that does not obstruct the driver's vision (see this instructable.) You may want to center the QR code between defroster wires, but I found my QR scanner can read the code anyway!