Is there a bed between a twin and a full/double?

I know there usually isnt...but are there specialty made beds? Has anyone ever heard of a bed in between these 2 sizes. If so, where would I find it?

They used to make a 3/4.I think that you can only get them custom now, which would mean that your linens would also have to be custom. I would make do with whatever you can fit into the room. Queen has become the norm.

Sofa cum Double Decker Bed!!