“Vulkanite” schwarzes Kunstleder (black synthetic leather)
Körperbedeckung (body covering)
In Germany in the 1930s, an early type of black plastic synthetic leather called “Vulkanite” was used as the body covering of military and commercial Dienstgläser (service glasses) manufactured before World War II.
This “Vulkanite” schwarzes Kunstleder (black synthetic leather) Körperbedeckung (body covering) was the most common Dienstglas body covering used by the German armed forces (and also by most of the other armed forces of Europe) during the early years of the Second World War.
TM 30-506, WAR DEPARTMENT TECHNICAL MANUAL, GERMAN-ENGLISH MILITARY DICTIONARY, WAR DEPARTMENT, 20 MAY I944
The TM 30-506 manual describes “Vulkanite” schwarzes Kunstleder (black synthetic leather) Körperbedeckung (body covering) as “Kunstleder n” artificial leather.
Schwarz „Reis“ Körperbedeckunglack “rice” body covering)
Early in the Second World War, a black Rauhlack (rough lacquer) body covering called schwarz „Reis“ Körperbedeckung (black “rice” body covering) also became a common Dienstglas body finish.
This new Dienstglas body covering began to replace the black “Vulkanite” (synthetic, leather-like, early plastic) body covering material on the housings of German field glasses.
The particular consistency of this black „Reis“ (“rice”) Rauhlack (rough lacquer) body covering was achieved by mixing crushed rice or finely granulated cork meal with black lacquer paint.
This black „Reis“ (“rice”) Rauhlack (rough lacquer) body covering became the most common Dienstglas body covering as the war progressed through 1942 and 1943.
Sandgelb (sand yellow) paint finish 
As wartime material shortages and minimal manufacturing techniques went into effect, paint alone eventually became the prominent Dienstglas body covering.
Dark gray paint and dark green paint began to be used, in place of the pre-war black “Vulkanite” simulated leather body covering and the early-war black “rice” Rauhlack (rough lacquer) body covering.
A Wikipedia article entitled “List of RLM paint designations” includes the colors “RLM-79, SANDGELB (sand-yellow)” and “RLM-79, SANDBRAUN (sand-brown)” within a list of RLM (Reichsluftfahrt Ministerium) paint designations specified by the German Ministry of Aviation from 1933 through 1945.
As World War II entered its fifth year in 1943, shortages of industrial materials in Germany became so severe that even black pigments became unavailable for wartime paint production.
In September 1943, the standard Reichsluftfahrt Ministerium (German Ministry of Aviation) listed paint, RLM-79, SANDGELB (sand-yellow), was designated einheitsfarbe Europa (single color Europe), and was ordered to be used on all military equipment of the German armed forces, including tanks, trucks, vehicles, artillery, and all kinds of smaller equipment, including Dienstgläser, and other optical equipment.
In previous years, RLM-79, SANDGELB (sand-yellow) had been a standard paint color used on Luftwaffe aircraft, tanks, trucks, and other vehicles of the German army in North Africa, Greece, and other Mediterranean operating areas. Referring to the Sandgelb (sand yellow) paint, a Wikipedia article entitled “Wehrmacht uniforms” within the “Tropical uniform” section states, “For combat situations, standard steel helmets field-painted in a tan color were issued, usually vehicle interior sand-yellow (sandgelb) or exterior brown-yellow (gelbbraun).”
Following the order of September 1943, Sandgelb (sand yellow) paint was specified for use in the manufacture of all new optical equipment, and existing optical equipment was ordered to be repainted with the new Sandgelb (sand yellow) color.
The Deutsches Afrikakorps (DAK), the German expeditionary force sent to support the Italians in North Africa, and commanded for a time by Field Marshal Erwin Rommel, fought from March 1941 to May 1943. Outgunned, outnumbered, and isolated from resupply, the German armed forces in Africa were compelled to surrender in Tunisia on May 13, 1943.
Sellers on eBay, and other similar sites, often erroneously claim that service glasses painted with the Sandgelb (sand yellow) color are somehow related to the German “Afrika Korps“. In reality, there was no German “Afrika Korps” after March 1943, fully three months before the September 1943 order that specified the use of Sandgelb (sand yellow) paint on German military equipment in Europe.
The eBay myth that tan painted German military items must be “Afrika Korps” is similar to the eBay myth that every French military item must be “Foreign Legion.” It makes for a good “sales story,” but it’s just not true.
Bakelit (Bakelite) used in Dienstglas body construction from 1944 to 1945
TM 30-506, WAR DEPARTMENT TECHNICAL MANUAL, GERMAN-ENGLISH MILITARY DICTIONARY, WAR DEPARTMENT, 20 MAY I944
The TM 30-506 manual describes Dienstglas Bakelite body construction as “Preßstoff m” plastic.
Bakelit is the German word for Bakelite, an early plastic developed by the Belgian-American chemist Leo Baekeland in Yonkers, New York, in 1907.
Before and during World War II, Bakelit was used in the manufacture of carrying cases for Dienstgläser (Service glasses), as well as bayonet handles, pilot goggles, field telephones, water bottles, storage boxes, anti-personnel and anti-tank mines, and thousands of other items of military equipment.
Toward the end of the war, Bakelit was even used as the last gasp, last ditch major production material for some of the very last production service glasses of the German armed forces.
German manufacturer logo markings on pre-war military equipment are easily identified. The German military knew that obvious equipment manufacturer markings would easily provide enemy intelligence services with excellent targeting information for bombing.
In 1924, the German Federation of Electrical Engineers presented guidelines for material classification, as many of their members were involved in Bakelit (Bakelite) production. The national material proofing house (Materialprüfungsamt), based in Berlin, Dahlem proposed marking standards.
In December 1938, the “MP” (Materialprüfungsamt) devised a common marking system, incorporating manufacturer information and chemical composition of the Bakelit (Bakelite) material, could be displayed.
The marking seen on Bakelit parts is an “outer circle”
an “M” for Material and a “P” for Prüfung (Testing)
For example: “43. Dynamit AG, vormals Alfred Nobel und Co, Abt. Zelluloidfabrik, Werk Troisdorf.”
“T” for Carbolic Resin (Bakelite) with a textile based filler