21bf31ab___open_books_for_an_open_world_Surface_types_Description
[Surface type] Unjoinable [Description] 
This surface type is identical to the smooth surface type with the exception that building tools made by ROBLOX and part of the studio will not create joints between surfaces with this surface type and other surfaces.
ROBLOX Game Development/Single page version - Wikibooks, open books for an open world