Full Idea
There seems to be no way of identifying a substratum as the bearer of qualities without qualifiying it as bare (having the property of being bare?), ..and they cannot be used to individuate things, because they are necessarily indiscernible.
Clarification
A 'substratum' is also known as a 'bare particular'
Gist of Idea
A substratum has the quality of being bare, and they are useless because indiscernible
Source
Cynthia Macdonald (Varieties of Things [2005], Ch.3)
Book Reference
Macdonald,Cynthia: 'Varieties of Things' [Blackwell 2005], p.113
A Reaction
The defence would probably be a priori, claiming an axiomatic necessity for substrata in our thinking about the world, along with a denial that bareness is a property (any more than not being a contemporary of Napoleon is a property).