Calibration Standards are known concentrations of components of interest used to confirm or determine component concentrations in samples. Calibration standards are used for quality assurance, quality control, measurement and balance, quantitative sample analysis and custody transfer. They should be used anytime it is important to know the composition of your samples and to determine if your process is performing as expected. There are different techniques for the manufacturing of calibration standards. The following is a partial list of commonly used practices: Pressure blending, combination of pressure blending and gravimetric blending, gravimetric only, analytical only, gravimetric and analytical, gravimetric verified by analysis and gravimetrically prepared NIST (National Institute of Standards and Technology) traceable by weight with the gravimetric values verified by one or more analytical methods. This paper will discuss how to properly manufacture a gravimetrically prepared, NIST traceable by weight calibration standard in which the gravimetric values are verified by one or more analytical methods. The gravimetric uncertainty of this standard is = ± 1% per component