1. Select object with Pick tool then click Info tab in Tool Options palette and the Type should be listed as Solid.
2. Turn ON the Show Direction option in Shaded Work Display Options and arrows are visible on any edge of a surface that is not stitched to another edge.
3. To search your entire project select Print Prep tool, select Non Solids option and Highlight Segments option, then click a blank area and your entire model is analyzed and any open boundaries on “non-solids” are highlighted. Note, this option is only available in formZ Jr and formZ Pro.
4. Use Select By Criteria palette to select just “solid” objects. An alternate method would be to select every Topology Type except “solid” and observe if objects are selected that you thought were solid. Note, this option is only available in formZ Pro.