Thanks Nic. It just so happens I was perusing Cookson's enamelling section and had spotted those

Jinks McGrath says wet & dry works in one of her books but on second thoughts it'll be a lot easier with a block!

I'm thinking I might make use of the freepost event to order some supplies in, which will make 3 orders in 4 days, oops! I think Cookson's should have you on commision Nic