Importing and Setting up in Painter
Substance Designer Community Wiki
https://support.allegorithmic.com/documentation/display/SPDOC/Creating+custom+effects
For Making SSS materials in designer use the official MDL preset
https://share.allegorithmic.com/libraries/4481
A generic effect will be applied on all the document channels, including opacity. A generic filter can be :
The input node of the effect must have the identifier or usage defined input and its output node must have output. Note that color based fitlers can't be used on the mask of a layer, only grayscale fitlers will be compatible.
A generator behave like a filter, the difference is that there is no input node other than the additional maps. If you need to read a channel from the texture set, then you want to make a filter.