It has been said in one of the media reports that the kidnapper was reported (by MK) to have had black hair on his arms and the backs of his hands. Because of this, I always discounted the idea that the kidnapper wore gloves.
BUT I was recently reading the book about the Zodiac killer by Robert Graysmith. A lot of the letters written by the Zodiac are reprinted in that book. In one letter, Zodiac boasts of leaving no fingerprints because he had covered the tips of his fingers and parts of his palms with airplane glue, which he then let dry, to form a coating. There is also a product called (I think) New Skin. I have used this on small cuts, such as paper cuts. It is a liquid bandage. You brush it across the skin and it dries in a film. It does not come off through mere exposure to water--you have to scrub or peel it off. It protects small cuts very well.