In making a Palladium print I paint a light sensitive emulsion onto the watercolor paper under subdued light in the darkroom.
While painting the solution onto white paper it can be diffcult to tell if there is an even coating. I want to make sure there is an even coating under all parts of the negative so that the darkness (density) will be consistant throughout similar areas of the print.
The less light blocking ability the negative has the darker the image will be in those places.
The prints have a weird / different looking border because this is the area that I have "painted" the emulsion onto the paper but there is no negative to block light from this area.