Hi @Peppers,
I believe you have an aluminium clad caravan from your previous discussions.
You'll want to start by giving it a good cleaning to remove any contaminants that could reduce the adhesion of your paint. Start by giving it a good clean with warm water mixed with sugar soap, then allow it to dry.
It would be worthwhile starting with a primer such as this White Knight Rust Guard Medium Grey Metal Primer Paint to ensure that the topcoat sticks and your wonderful design lasts as long as possible.
I'd suggest using an epoxy enamel paint designed for metal, such as this White Knight Rust Guard Gloss White Epoxy Enamel Paint.
It can be tinted to a wide variety of colours to suit whatever design you are looking for.
Let me know what you think and if you have further questions, please don't hesitate to ask.
Jacob
