These bobble-edged coasters are quick and easy to make. I used Rowan handknit cotton in aubergine (348), sugar (303), gooseberry (219) and pesto (344) with a 4mm hook. The pattern is written in UK terms.
To start I made a magic ring and then worked 12 dc into the ring before pulling tight. If you don't want to start with a magic ring make 6 chain, slip stitch into the first chain made to make a ring and work 12 dc into the chain ring.
The coaster is worked in a spiral so it's a good idea to place a marker in a contrasting coloured yarn at the beginning of each round: place the marker tight against the loop on the hook then work the first dc in the round, catching the marker into position.
Work 1 dc into each of the remaining 12 dc of the previous round. At the end of the round pull out the marker and place it against the loop on the hook to mark the beginning of the next round.
Work 2 dc into each dc to end. You should now have 24 dc in the circle.
Work 1 dc into each dc to end
Work 1 dc into first dc, 2 dc into next dc, *1 dc into next dc, 2 dc into next dc, repeat from * to end. You should now have 36 dc in the circle.
Rounds 6 and 7
Same as round 4
Work 1dc into each of first 2 dc, 2 dc into next dc, *1 dc into each of next 2 dc, 2 dc into next dc, repeat from * to end. You should now have 48 dc in the circle.
Rounds 9 and 10
Same as round 4
1 dc into each of first 3 dc, 2 dc into next dc, *1 dc into each of next 3 dc, 2 dc into next dc, repeat from * to end. Sl st into first dc.
Ch 3 (this counts as first tr), MB (make bobble) as follows: work 5 tr in next dc, remove the hook, insert the hook in the top of the first of these 5 tr, then back into the loop of the 5th tr and pull loop through the first tr, chain 1, *1 tr into next dc, MB into next dc, repeat from * to end. Sl st into 3rd of the 3 ch at the beginning of the row. Weave in ends.
Note: bobbles are a bit yarn hungry so you could save a bit on yarn by evenly spacing them out a bit, replacing some of them with trebles.
And that's it!