The double brim in the heavier yarn and the textured sides make this really cosy. The top as worked has a slightly ‘pie crust’ effest; if you prefer it flat simply block with a disc of the appropriate sizeThe gauge on the brim is approx 19st to 4 inches over garter st, due to the nature of the yarn there is quite a lot of stretch in this.The Ophelia could be replaced with a lightweight chunky or one strand of Dk and one strand of a lace weight mohair. A 10st reduction at each stage would probably reduce size by about 2 inches and allow all shaping to remain the same