If that box is checked, you will skip the prints submission page and the sizes closest to the image you have submitted will be selected. If you leave the box unchecked, you will be brought to the prints submission page where you can customize your products to your hearts content.
Keeping the box unchecked is most definitely the best option to choose, in my opinion. I like to have control over every piece to make sure it will look good when someone buys it.
On the flip-side, if you're a photographer and your source file hasn't been cropped at all, there is an excellent chance the 1.5:1 image ratio will work by default. Our system will see that and give you those print sizes already set up. I would still recommend personally looking at them, but in cases like that, it is most likely safe to submit the default settings. No Art Gift products will be selected by default. These include mugs, magnets, and calendars. Those must be manually added.
If you're unsure which you like better, un-check the box and see what prints it gives you. On the prints submission page, what you see as checked are the default sizes.
