Certifiable Scraps are available from various lodging cards, and other storylets throughout Fallen London.
Certifiable ScrapScraps can be exchanged on The Relickers's opportunity cards for
Perhaps Mr Cups will recognise this as something delightful. [When the Relickers appear, you'll be able to trade these Scraps for many things…]
It is worth noticing that this is often one of the first ways to gain new items in these categories.