The red line around the sides of the pages is where we cut the pages. We recommend keeping your photos and text at least 5mm within these lines to avoid being cut off. For all backgrounds and full photo pages, the photo/background must be stretched all the way to the blue line. If the photo/background is on the line or just before the line then there may be white strips on the edges of the pages once they are cut. The black line in the centre is to show the centre where the pages meet.