This PaintShop Pro script allows you to enter a set of dimensions (number of rows and number of columns), and it automatically draws a grid according to the dimensions of your image.
Although there are many uses for this, the main goal of the script is to facilitate the arrangement of images for Picture Tube creation.
See an example of its use here:
Custom Picture TubesOnly tested in PaintShop Pro 2020 and X9 on Windows 10, however, other versions may be compatible.