how to print 2 5x7 photos on one 8x10

You can not - you need small borders for multiple up prints - you could print two 4.75 x 7 photos on an 8x10

Not sure why that restriction is there - suggest a change to Apple - iPhoto menu ==> provide iPhoto feedback

LN

If you have Pages from iWork you can do it as long as your printer supports 8 x 10 borderless printing.

1 - create an 8 x 10 page in Pages.

2 - add the two cropped 5x7 photos to the page.

3 - arrange them so the both fit on the page .

4 - print.

If you don't have Pages you can use any 3rd party image editor that supports layers.

OT