A presentation space consumes a considerable amount of memory, so you should delete it when your application no longer requires it. Use GpiDestroyPS to delete either a normal or micro presentation space.
When you finish using a cached micro presentation space that you accessed with WinGetPS, release it with WinReleasePS. You need not delete a presentation space that you accessed with WinBeginPaint. PM does this for you when you call WinEndPaint.