Full Idea
A rival to the bundle theory says that, for each substance, there is a constituent of it that is not a property but is both essential and unique to it, this constituent being referred to as a 'bare particular' or 'substratum'.
Gist of Idea
Each substance contains a non-property, which is its substratum or bare particular
Source
Cynthia Macdonald (Varieties of Things [2005], Ch.3)
Book Reference
Macdonald,Cynthia: 'Varieties of Things' [Blackwell 2005], p.111
A Reaction
This doesn't sound promising. It is unclear what existence devoid of all properties could be like. How could it 'have' its properties if it was devoid of features (it seems to need property-hooks)? It is an ontological black hole. How do you prove it?