I’m trying to wrap my head around creating custom detail components, but can't seem to find an answer for this problem.
Using the standard Revit Metric Detail Item.rft file, I have drawn the flowing component using Filled Regions/Masks.
If I draw a Generic 100mm Wall and then place the detail component on top, I get black lines on either side of the masked region. I’m guessing this is because I have set the lines on either side Invisible.
Is there any way around this problem?
It looks like you are trying to create a pocket door... May I inquire why you would want to detail this and not use an actual door component?
My first thought is the details is not covering all of the wall - the thickness is off. I recreated it the attached image is what I have...
LD
The Problem is that the Invisible Lines have a Line Thickness of 1 (not changeable) whereas the Wall has a much greater Line Thickness, This causes the 'fatter' lines beneath to spill outside of the masked region. If you toggle Thin Lines, you can see for yourself.
You will have to increase the width of the Masking Region to account for the thickness of the model lines which need to be masked. You can build an "extension" to the invisible line area in lieu of making the Detail Lines wider. See image below.
On a side note, Detail Items only appear in the View in which they were created. Is this something that should be represented as a Model Element, meaning an element that actually breaks the Wall in lieu of masking it?
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Lisa & Corey, thank you both for the tips, I'll give that a shoot 
Lisa to better answer your question, yes I agree... I would generally use a proper pocket door to insert in the wall, but my true reason for the test was that when I insert a pocket door in a thinner wall, the line thickness are so bold, that it looks like a blob when viewed at scale 1:100.
Also the other reason was, I was toying with the idea of creating a generic pocket door with several "graphical" plan view options, just like in your attachment examples where you have the panel filled with black, then the other white. I was thinking if I create several "visual" versions, I can then simply apply a on/off parameter, allowing me to choose which graphical representation would look best on any given wall.
Does that make sense? I understand the "Best Practice" would be to create individual family's, but sometimes I just need a quick and dirty option to get through 
Hi tonkata - it is not a problem what you are doing... Sometimes it is good to get the frame of mind to fully understand that someone is thinking...
It makes total sense to make them in one family and then use parameters to control the display. Sounds like some great options and well thought out.
LD
