David,

>>I building a very small app that only uses about 5 Base Classes. Are you recommending that I break myBase vcx into different files?
>
>If your app makes use of all 5 of those classes then you have appropriate packaging. If you have a classlib that contains 20 classes and your app is only using one of them, that's a candidate to have it's own classlib.

I'm having a problem reconciling this with my situation. Hopefully I'm missing something.

I have a classlib that has 20 classes in it.
App1 uses classes 1-5
App2 uses classes 3-8
App3 uses classes 7-15
etc.

I can't create a separate classlib for each app, and still keep all the inheritance that I want.
If I subclass classes 1-5 for App1, I still have the parent classlib with all 20 classes in it in my app. In addition I have 5 more subclasses making 25 in all.
If I copy classes 1-5 into a separate classlib for App1, then I eventually have a maintenance headache trying to make sure that all classlibs get the same modification. This probably won't be a problem with the very topmost classlib because it has very minimal modifications. But every other level could be a nightmare.

I do have a classlib for each app. It contains only those subclasses that are used in the app. But they are all subclassed from classlibs that have more classes than the app uses.
example: App1.vcx contains class txtUserNum. txtUserNum is subclassed from txtInteger in TextBoxes.vcx. TextBoxes.vcx contains txtInteger, txtNumber, txtCurrency, etc that are all subclassed from txtBase in myBase.vcx. myBase.vcx contains txtBase, cntBase, chkBase, frmBase, etc.

Right now when I make a modification to chkBase in myBase.vcx, App1.exe gets bigger even though there are no checkboxes in App1.