Many case-based reasoning systems have been developed to aid designers by providing them with libraries of prior design experiences. Traditionally, these systems are implemented as stand-alone \external memories" for the designer to query manually. This paper presents a contrasting approach that integrates proactive case retrieval into the designer's normal task processes, automatically tailoring information selection and presentation emphasis to t changing designer needs and attention ow. The paper presents a set of principles for this integrated intelligent design support and describes their application in the Stamping Advisor, a system to support design feasibility analysis for sheet metal automotive parts. The Stamping Advisor interface proactively provides design- ers with relevant information to support feasibility analysis, automatically prepares their information products, and un- obtrusively gathers the information needed to generate new cases to improve the quality of future support.