Often people want the images to flow over the edge of the pages and look borderless.
This is achieved with a technique called bleed.
When we print books, we print the pages on larger sheets of paper and trim them down to size after printing, cutting off some of the printed area.
The RapidStudio software accommodates for this by allowing you to drag images over the edge of the page.
If you want your images to "bleed" please drag them at least 3mm over the edge of the page.
It's always important to make sure that they go over the edge, so that if the page isn't cut 100% on the cut line, there aren't slivers of white or background showing through between the edge of the image and the edge of the trimmed page.
It's also very important to keep any important detail inside the safe area. If a person's head or a bird's beak strays into the small gap between the safe area and the edge of the page, there's a real possibility it will be chopped off.
If you have an image that just isn't fitting nicely, if when you give it bleed some important image details start to cross the safe area line, you'll need to decide if you can rather use a different image, or adjust the layout of the page to either be completely within the safe are and not bleed at all, or sacrifice the detail crossing the safe area line.
Unfortunately, this is a trade off that sometimes has to be made by the designer.
Anything that bleeds must go 3mm beyond the edge of the page
Anything important must end within the safe area line.
Pictures should never end on or between the safe area line and 3mm beyond the edge of the page.
There is a detailed image attached to this article to study for more information.