Border for framing

[Rudesing]

I have been asked to design an A3 montage for a client. Does anyone know how much border/space I should leave around the outside of the photographs to fit under a mount / frame?

I hope that makes sense

Thanks

 

[swanseamale47]

It will depend on the fame, most don't have much rebate for glass but it does vary (and they might use a borderless frame) ask to see the frame and measure it yourself to be on the same size.