About Defining and Removing Sliver Surfaces
Slivers are very small and or very thin, high aspect ratio surfaces, or contiguous chains of surfaces. Even though a quilt may be completely closed, the presence of slivers in the quilt may cause problems in downstream applications such as manufacturing. You can quickly and easily define or identify slivers in an imported model using the Define Slivers tool or the Search Tool.
If you use the Define Slivers tool, you must manually select the sliver surfaces in the graphics window. When you select the sliver surface, the edges that correspond to the sliver are automatically added to the Side 1 and Side 2 edge collectors of the Define Slivers tool. However, for some slivers where there is ambiguity, you may have to manually define the sides of the sliver. You can also modify the automatically selected sides in the side collectors, if required.
If you use the Search Tool, you must specify the rules for the search operation by using attributes such as size and value to find the slivers. After you specify the search criteria, IDD automatically searches for slivers in the active component node or active set of surfaces and highlights them in the graphics window.
After defining a sliver, you can remove it in several ways. You can add the sliver to the wireframe and then click > 
Repair. The surfaces between which you defined the sliver must belong to the same component node. Adding the sliver to the wireframe results in the deletion of the sliver surface or surfaces and the creation of black wireframe pieces, representing the gap that is left by the removal of the surface. If Repair fails to close the gaps created by the removal of the sliver surface, you can use > 
Close. Close converts the black wireframes to satisfied wireframes.
Repair. The surfaces between which you defined the sliver must belong to the same component node. Adding the sliver to the wireframe results in the deletion of the sliver surface or surfaces and the creation of black wireframe pieces, representing the gap that is left by the removal of the surface. If Repair fails to close the gaps created by the removal of the sliver surface, you can use > Close. Close converts the black wireframes to satisfied wireframes.Alternatively, after defining or searching for the slivers, you can click > Close without adding the slivers to the wireframes. The Close tool removes the sliver surface or surfaces and attempts to close the gap left behind in one step. A sliver may be closed between any surfaces that are logically joined by a Combine node. They must belong to a single component. However, slivers cannot be defined between the base-level nodes.
Close without adding the slivers to the wireframes. The Close tool removes the sliver surface or surfaces and attempts to close the gap left behind in one step. A sliver may be closed between any surfaces that are logically joined by a Combine node. They must belong to a single component. However, slivers cannot be defined between the base-level nodes.You may delete slivers that are in the selection buffer. This effectively deletes the sliver surfaces without creating black wireframe pieces or attempting to close the resulting empty space in the quilt. You must then either define a gap or manually repair to patch the quilt.