A systematic methodology for design of tailor-made blended products has been developed. In tailor-made blended products, one identifies the product needs and matches them by blending different chemicals. The systematic methodology has four main tasks. First, the design problem is defined: the product needs are identified, translated into target properties and the bounds for each target property are defined. Secondly, target property models are retrieved from a property model library. Thirdly, a mixture/blend design algorithm is applied to obtain the mixtures/blends that match the design targets. The result is a set of blends that match the constraints, the composition of the chemicals present in the blend, and the values of the target properties. Finally, the mixture target property values are verified by means of rigorous models for the properties and the mixtures. In this paper, the methodology is highlighted through two case studies involving gasoline blends and lubricant base oils. (C) 2014 Elsevier Ltd. All rights reserved.