Switch layers not interpolating?

[SuperSGL]

To start - it's a mouth as a mask so the tongue can move separately. Two layers inside a mask (both with the same name 'mouth' 'tongue' ) and this whole set up is copied as another switch layer, the mask folder the typical Ohh Smile closed but when I animate with interpolation on, it goes from 'closed' to 'smile' no morph. Did not add or subtract any points just moved them but with some curvatures changed as well as line widths.
So, which one of these is causing the switch not to interpolate? (assuming I'm clear enough of my set up)
thanks

[slowtiger]

Interpolation only works on the layers inside the switch layer, not inside layers inside the switch layer. You have to build your mouth in just one layer - it's possible.

[synthsin75]

You probably need to mask using the switch layers instead. viewtopic.php?p=164763#p164763

[SuperSGL]

Just what I'm looking for Thanks! the file is an excellent example. very helpful!

[synthsin75]

Glad it helps.