A multivariate approach to the analysis of cured resin blends comprising cyanate ester and bismaleimides is reported. An analysis of samples subjected to accelerated ageing tests by immersion in water at temperatures up to 70 degreesC shows that simple near infrared spectroscopic measurements on virgin materials can predict dynamic mechanical thermal analysis results, and provide correlations with thermogravimetric analysis. This suggests a rapid screening method for a range of materials, perhaps in conjunction with a combinatorial approach to advanced composites manufacture.