Historically, kaolin has been considered as a semi-reinforcing filler in rubber compounding applications.  Improvements in kaolins’ reinforcing capabilities’ had been generally directed to applying a surface treatment to kaolin directly previous to its addition to the rubber mix.  These surface treatments were organofunctional silanes, crosslinking resins, or other chemistries including combinations thereof.  These surface treatments were used to increase bond energy of the kaolin to the rubber; this approach, though effective, lacks flexibility with the wide range of elastomers that have evolved since inception.  An alternative approach we have been investigating is to increase the reactivity of the kaolin surface to a coupling agent making the in-situ reaction more efficient and thereby increasing the reinforcing potential of kaolin with a variety of silanes suitable for a variety of polymers.  This paper discusses initial attempts and compares rubber test results of this approach to conventionally used, similar sized fillers; a new balance of high ultimate strength with high flexibility is observed and options and opportunities are discussed.