I've used a GDI Viewer and it seems that when I close a form it leaves many Font Object Type objects. How do I disposed these 'Font' objects when I close the form 'onFormClosing'

I've used the following below to try to do a garbage collection onFormClosing but it isn't getting rid of everything GC.Collect(GC.MaxGeneration, GCCollectionMode.Forced); GC.WaitForPendingFinalizers();