Although it is fairly easy to create slanted slats, it can also be a little tedious.
This script will create those slanted slats on your image in record time. You can choose how many slats/pieces you want and the script will do all the calculation for you. You get to choose the angle of the slants, the number of pieces and the gap between them.
But once the design is done, you can keep the pieces on a single layer, or on individual layers, or you can even turn that design into a mask.
In some versions of PSP (X9 and older), you can also group some slats if the cut happens to fall on an unwanted location, like in the middle of someone's face. This feature is not available in versions 2018 and up.
Compatible with PSP8 and up.