leasing decals

When NREX "covers up" the former owner's name what adhesive do they use? It looks like a large wide roll of duct tape.
http://www.railpictures.net/viewphoto.php?id=90189
http://www.railpictures.net/viewphoto.php?id=78541
http://www.railpictures.net/viewphoto.php?id=75026

More than likely it's an adhesive backed vinyl of the type used for graphic designs. Basically peel and stick product it is easily applied and holds up well to the elements.

Having been on multiple SD-90's, and 40's, from UP, as well as other units, I have seen no tape, yet. It's all paint, masked out, or simply applied, with a roller. I was going to "uncover" as SD-90, one night, while waiting for a meet. Imagine my disappointment, when I went back with my handy putty knife, and found thick, textured black paint. NO chance of returning those paints. Although the lettering IS vinyl, the cover-up is paint. Most of the time, the railroad itself paints out the reporting marks, with their own paint. (one fine day, many years ago, on the NYS&W, another engineer (Raul), and myself spent a few hours, peeling the paint off of an LV Geep, returning almost all of the original lettering, hidden under a quickie paint job!!! ) Kinda like a hobby, with some of us, resurecting "fallen-flags"............

well there goes that idea, "accidentally" removing the number patch off a patched SP engine...

Well HLCX just paints over it. I saw an ex-MRL Geep on the Local this morning, and it had MONTANA RAIL LINK painted over and had HLCX on it. I think it was one of the old Morrison Kundson MRL locos too...