To make this, you'll need: fabric, freezer paper, scissors, iron, pencil, craft knife, cutting mat, fabric paint, and a foam brush. I used a length of jersey from the fabric store—you know, T-shirt material. Soft and comfy, and doesn't fray around the edges.
I sketched an abstract design onto the uncoated side of the freezer paper. These were just messy hexagons and pentagons that got gradually smaller. A pattern of all straight lines is much quicker to cut than curves. Since I wanted the graphic at both ends of the scarf, I traced the original design onto a second piece of freezer paper.
With an X-acto knife, I cut out the shapes. Each piece took about 20 minutes—though I was watching HGTV at the same time, so you might be more productive and less likely to cut off a limb if you pay closer attention to what you're doing.
I ironed the stencil shiny-side down onto the fabric. The freezer paper sticks like magic.
Using a foam brush, I painted in the shapes. Be sure to place a garbage bag or something protective under the fabric just in case a little paint soaks through. I used Pebeo Setacolor fabric paint, but I wasn't thrilled with the coverage. That stuff is washable after you set it with an iron, which is great. But I wanted a more opaque white, so I brushed on a second coat of white acrylic paint. Will it wash off? Probably not. Do I care, because I ever wash scarves? Probably not. (Next time I might get some Tulip brand Soft Fabric Paint and try that.)
I let the paint dry and tore off the paper stencil. Then I trimmed along the scarf edges with a rotary cutter so the design would extend off the sides.