Traditional methods for partial envelope analysis run into difficulties in the presence of tremolo and noise. This paper investigates an alternative method of analysis that uses a variety of non-linear warping techniques to match a synthetic envelope template to the partial envelope. Generation of suitable templates is discussed and the variety of implementations for the warping algorithm is examined. A complete procedure for matching the template is then explained and justified. Application of this procedure to partial envelope analysis of flute sounds is described and the results presented demonstrate the best choice of warping implementation. This technique allows for better envelope segmentation thus enabling improved modelling in representations such as the Timbre Model