Unusual types of gramophone records did have etched labels as well, with many (if not all) also featuring a little etched picture of Thomas Edison. The Gramophone company etched their logo at the blank side of their single sided records in the early 1900s, in the same way, Some later single sided Red Seal records by Victor had a pattern with the word Victor on it. After having already released both colored vinyl singles and picture discs in the 1980s, Canadian rock artist Bryan Adams issued a 12" single of "Can't Stop This Thing We Started" in autumn 1991, which had the front cover photography
Polymer fractionation Polymer fractionation Polymers are chainlike molecules that are made of the same repetition unit. With a few exceptions such as proteins, a polymer consists of a mix of molecules with different chain lengths. Therefore average values are given for the molecular weight like the number average, the weight average or the viscosity average molar mass. A measure for the width of the molecular weight distribution is the polydispersity index. The targeted manipulation of the molecular weight distribution of a polymer by removing short and/or long chain material is called polymer fractionation. The molecular weight of polymers has a large influence