The Pacific Coast Air Line Railway is set in Central California. Visiting that region and taking pictures new techniques needed to be developed. I live in Delaware so the west coast scenery is very different.
This is a picture of a rock formation out on California Highway 101 south of Santa Clara. It is either stratified limestone, mudstone or shale. Most of the hills are consistent with this look. I needed to develop a technique to model these rocks.
This is industrial cork gasket material. I obtained it from McMaster-Carr, they have a website. It is 1/16 and 3/32 in thick, it is available in many thicknesses. I broke them into pieces and glued them together making strata.
I had made stratified rocks from ceiling tiles in the past. The would not produce the effect in the picture.
Paint the cork with either ZAP or Kilz2 acrylic primer to seal the cork.
I applied a wash of Brown Rit Liquid Dye straight from the bottle. Thin sedimentary rock is in the realm of possibility. Mocked up quickly this will be put to future use on the layout. A little more work in arranging the cork and it would be a dead ringer.
This is a test mockup seeing the feasibility of making thin strata.
Engineer Bill with the rock strata, he is a 1/43 O scale Preiser figure.