For this pattern you can use any kind of cotton yarn for hook size 2,5.
The coasters are 8cm wide and made in the same way as mochila bags. The coaster is made only with single crochet, the design appears by changing the color.
Some tips about mochila crochet are included, but not a complete tutorial.
The pattern contains 4 coasters with star/flower design, 2 of them with some extra variations on the design, and an easy bonus pattern for beginners.