One gets the impression reading the marketing blurb, especially with finleyville's comments, that they are far more about being jewellery with all the right "boxes" checked, than anything else. Naked? - check, Cotton - check, Crystals - check, Gold-Plated - check.
Even their marketing is somewhat misleading like this statement. Cotton at 1.3-1.4 is the Google value, and is based on a particular density, and being absolutely dry. Foamed polyethylene is 1.6, foamed polypropylene can get to 1.25, and both are far more moisture immune. Cotton's dielectric constant changes so much with moisture that this property is used in textile processing for quality control.
Why cotton?
Cotton
possesses excellent dielectric properties in respect to signal
fidelity. This parameter is commonly referred to as the dielectric
constant. Cotton has a value of 1.3 (1 is the ideal) 2-5 are the common
values for most insulating polymers. For example Fluorocarbon has a
value of 2.1 and Polyethylene a value of 2.25.