On 11 Jul 2013, at 20:37, Ramon Pedrosa <[log in to unmask]> wrote:
[...]

> I realize my iMac thinks I will use my own printer which is a Stylus Photo
> R310 which will not take A3 size paper.
> 
> What do I do please

You may be able to resolve the issue by adding a virtual printer which can take the required paper size.

You will find the instructions here:
http://support.quark.com/Knowledgebase/ArticleDetails.aspx?kbarticleid=bc63f28b-1c94-de11-93a0-00155d642a02

Hamid