Accelerated testing serves to determine the coating's ageing behaviour. Thus it has become an indispensable tool of quality assurance for monitoring coating development as well as series production over the last 100 years. This book shows how to identify the weak points of accelerated testing, to avoid errors and thus to boost confidence in the test results. Boasting a compact theoretical section on the key fundamentals of paint ageing, this book imparts the necessary expert knowledge that will enable paint testers to make an informed choice about the methods and instruments to employ in accelerated weathering.