Umber -a natural brown clay pigment which contains iron and manganese oxides. Its name derives from the Latin word umbra (shadow) and was originally extracted in Umbria, a mountainous region of central Italy. It has been used as a pigment since prehistoric times.
Topology- is a major area of mathematics concerned with spatial properties that are preserved under continuous deformations of objects, the term is also used for a family of sets with certain properties that are used to define a topological space, a basic object of topology. For example a donut and a coffee cup with a handle are equivalent shapes, because each has a single hole.
Chairless chair produced by Vitra is a tool for sitting designed by Chilean architect Alejandro Aravena. A simple and witty idea, the textile strap joined into a loop measures 85 centimeters in length and five centimeter in width and wraps around the back and knees to stabilize the body and relieve tension while seated. http://www.vitra.com/chairless/