Hi angeliclight - the image that you bring in is basically just a reference guide for you to use as tracing paper. The size of the image file itself in pixel density won't really directly effect your model.

But a very high density image may just not work very well if you have an older video card that does not have very much video RAM on it. If you see stuff like slow screen redraws, or the images showing as all black when trying to use a very high density image, then you'll have to use a lower density image instead to avoid running out of memory on the video card.

High density images do tend to consume quite a bit of memory.

But if you have a fairly new video card those tend to have a lot more memory available on the card so it isn't really an issue there.

- Michael