The material was Hungry Caterpillar 'Encore food' 18" by 22". I bought it via a seller on ebay but I googled and quite a few people sell it too.
I created a triangle template which was 9" by 7".
Materials I used were:
fiskars rotary cutter
Hungry Caterpillar material (as above)
Red material (actually used a pillow case)
Blue material used about same amount as half a pillow case
9m bias binding
1) I cut as many triangles as I could from the hungry caterpillar material and again from the red and blue material making sure to note which way the pattern ran.
2) I pinned the HC material and red wrong side to each other, sewed a running stitch around the edge, leaving a two inch gap at the top of the triangle. I then snipped the corners of the triangle off and turned it the right way through using the gap. I then pushed the points of the triangle out using the pencil, before closing the gap using the sewing machine.
3) To make the HC material go further, each triangle was backed with red or blue fabric. This means the whole thing is reversible too. This was enough material to make two long strings of bunting.
4) I then laid out the triangles onto the bias binding (9m is enough for two strings). I positioned them so there was a 9" gap between them on the line, then pinned the triangles inside each bias binding and used the sewing machine to sew it in.