One difficulty in designing FRP is estimating the mechanical properties of the finished part. In many specifications, mechanical testing of a laminate is required to ensure that the design properties have been met. Some specimens may be curved although the test methods and equipment are designed for flat specimens. The test results obtained for curved specimens are potentially misleading as a result. Therefore, testing of curved specimens is not recommended. A discussion of how to interpret test results is presented. Keywords: fiberglass reinforced plastic, composites, testing, yield strength