The Damson Madder Cassidy Mini Dress features an oversized square collar with a tie front and long sleeves. The Damson Madder Cassidy Mini Dress features an oversized square collar with a tie front and long sleeves. Damson Madder was born out of a desire to make exciting designs, responsibly. From their North London studio, they craft playful, ultra-feminine designs meant to be worn again, and again (and again!). Think maximal style, minimal impact.