tegid o

I am finding it hard to work out how to customise matrixctrll. Can anyone explain why when I load the attached png as a cell image, the grid lines are so inconsistent?

custom-matrixctrl

You might try with a smaller source image. If you have this PNG as the source of matrixctrl that is scaled down significantly from the size of the original the problem will be more evident with a larger image as some of the grid lines may be "interpolated out of existence" so to speak.

Custom matrixctrl