Gaps in Mesh After Applying Modifiers I primarily use Blender for modeling 3D objects for use with a 3D printer. Most of my previous experience has been with simpler geometric models (like simple robots and the like) and I have recently started trying to make more organic objects. As part of the process I use boolean modifiers to reduce the amount of non-manifold geometry before printing. However, I've noticed that I get an issue where the meshes appear to be complete in solid view but not in wireframe view.




I'm not really sure where these holes come from, but they primarily seem to show up through the use of the Boolean modifier (this mesh was normal until I used the Boolean-Difference at the bottom). Once the mesh degenerates like this, I can no longer reliably combine it with other meshes. I'm hoping that this is a simple fix, but the problem is difficult to describe, so I haven't found a solution. Any help would be appreciated! Thank you!
The misleading representation of wires does not mean that your mesh has holes.

The inconsistent display of wires for faster viewport display can be "corrected" with the Draw All Edges option.

As you noted correctly, after the boolean modifier, the wire display is not consistent with the solid representation.


However, adding wire display in the Object's Properties Panel, shows the same wires in solid view.


To show all wires, enable Draw All Edges.




There are, however, many other tools, which are useful for cleaning objects. For example:  


the Mesh Analysis Section of the Properties Panel in the 3D View

the "Select Non Manifold Geometry" option in the 3D View &#9096; Ctrl&#8679; Shift&#9095; AltM
the 3D print toolbox addon