Custom Materials is a very handy feature of Solidworks as it can be used for calculating the weight of parts and assigning the correct material to parts.
When using a material regularly it can be handy to add it to the favourites list so rather than having to go into the Material Editor, you can select it from the list. This can save a lot of time when working with many parts.
However, after up-grading to Solidworks 2012, I noticed that if I tried to apply a custom material that I had added to my favourites list, it wouldn’t do anything. After a bit of searching and finding nothing to help, I contacted my support agent and they replied that it is a known issue (SPR#448697).
The work around they suggested was to put the Custom Material database in the actual default folder.
Windows Vista and Windows 7:
“C:\ProgramData\SolidWorks\SolidWorks 20XX\Custom Materials”
“C:\Documents and Settings\All Users\Application Data\SolidWorks\SolidWorks 20XX\Custom Materials”
The file must be named “Custom Materials.sldmat”
I did this and deleted my favourites, re-added the new custom materials and it worked so I thought I would post this in case anyone else is struggling to find the answer.