A3 is a European paper size, to the best of my knowledge. Pictures on the screen are (usually) 72ppi (pixels per inch), so if you measure an A3 sheet of paper, and multiply that by 72 (you may have to convert to metric, I 'spose). That will give you a screen resolution close to what you need.

If you're printing the picture, it's actually about 300 dpi. There's some math to do the conversion properly (future posters her will probably have it). Same general concept here.

Most printers can support several page sizes. Even American printers can do A4 in a pinch, so you should be able to load and print.

Hope that helps.

I wish I'd said that.. The Staircase Wit

anahl nathrak uth vas betude doth yel dyenvey..;)