Compositions created in Procreate app evolve within the selected format, a square or rectangle. Even if I have a white background for the image, the working area surrounds it with a darker color. Normally I use some color to the edge of the format which shows clearly when I post the image as in the square example below.
If I leave the background of the composition white it appears to float without borders over the white of the blog page. This is the case with all three of today’s images composed of multiple objects arranged in layers with textures added. To help contain the compositions on the white “page” I have added calligraphic (thick and thin) black line work to the top layer. These lines also add visual interest and strong contrast to the colors below.