a personal print - photobox - jpeg sizes/Aperture

[Iris]

Just a quick one - on photobox you can only upload jpegs, how do I export a file from Aperture and retain a large enough file size to get a big print?

The one I have uploaded is 3.9mbs and I've set the dpi as 300 and zero compression in my export preferences. The photobox site is saying that size will only give me an average print quality for 75cm x 50 cm hard backed poster print. It's nothing special, just something to brighten up my bedroom wall

 

[Iris]

Just a quick one - on photobox you can only upload jpegs, how do I export a file from Aperture and retain a large enough file size to get a big print?

The one I have uploaded is 3.9mbs and I've set the dpi as 300 and zero compression in my export preferences. The photobox site is saying that size will only give me an average print quality for 75cm x 50 cm hard backed poster print. It's nothing special, just something to brighten up my bedroom wall

Ignore above - took the photo on my husbands camera which was set to jpeg and not mine (which is defaulted to RAW)