Free Baby Carrier Sling Pattern

There are a lot of sling patterns on the web that are way easier to follow than that one, admittedly they are not patchwork, but I'd be very dubious about both the strength and the usability of a patchwork sling, you have to tighten them by pulling the excess fabric through the two loops, it's bad enough with a piece of fabric with no seams when you've got several pounds of baby pulling on it.

If you're going to put the effort into making a baby sling I'd use a pattern that has evidence of actually being tried and tested eg