RichViewMaxThumbnailCount Global Variable
RichViewMaxThumbnailCount = 50;
(introduced in version 15)
Specifies the maximal count of scaled images stored in TCustomRichView.
If RichViewMaxThumbnailCount=-1, all scaled images are stored.
Scaled images are stored for efficiency (to prevent recreating thumbnails on each redrawing).
Changes of value of this property do not affect TRichView components created before the change.