Here is what I came up with so far. – Not a complete list yet and maybe not all of the materials are 100% essential?
Just copy/paste the list and add materials into the matching category in the next posts.
Stones
Brick (New)
Brick (Old)
Concrete (Smooth)
Concrete (Weathered)
Marble Carrara (White)
Granite (Black)
Rock
[DONE] Paint / Coating (each in multiple colors: White, Black, Grey, Red, Blue, Yellow, …)
Highgloss Paint
Semigloss Paint
Matte Paint
Metallic Paint
Powdercoating (Glossy)
Powdercoating (Rough)
Plaster
Plastics (each in multiple colors: White, Black, Grey, Red, Blue, Yellow, …)
ABS (High Gloss)
ABS (Textured)
Polycarbonate (Transparent / Tinted)
Rubber
Wax
Organic
Hair
Fur
Skin
Leaf Shader
Grass Shader
Bark Shader
Ground
Soil
Lawn
Pebbles
Sand
Fabric & Leather (each in various colors and a basic pattern)
Cotton (Rough)
Silk (Smooth)
Wool (knitted)
Velvet
Leather
Paper
Paper White
Papyrus
Wallpaper
[DONE] Glass
Glass Clear
Glass Frosted
Glass Tinted
[DONE] Metal
Steel Polished
Steel Brushed
Aluminium
Aluminium Anodized (Colors)
Copper Polished
Copper Oxidized
Brass
Gold
Bronce
Stretch Metal
Chequerplate Aluminium
[DONE] Ceramic (each in multiple colors: White, Black, Grey, Red, Blue, Yellow, …)
Ceramic Glossy
Ceramic Tiles
[DONE] Liquids
Water Clear
Water Muddy
Coffee
Wine
Orange Juice
Blood
Wood (all in highgloss, semigloss, raw and worn variations)
Walnut
Cherry
Oak
Mahogany
Rosewood
Bamboo Veneer