The Next Generation of MS2A Resin: MS3

ABSTRACT MS2A was a reduced ketone resin and a preferred varnish for many painting conservators but ceased production in 2014. To remedy this, a new, more consistent manufacturing process has recently been developed and the next generation of resin designed with replicated chemistry is called MS3. Direct comparison between MS3 and MS2A is limited as no fresh samples of MS2A exist, so work presented here focuses primarily on the performance and characteristics of MS3 compared to literature reports of MS2A, and comparisons to older reference samples of MS2A. Refractive index, gloss, glass transition temperature, and molecular weight are presented. MS3 and comparative low molecular weight varnish resins were artificially aged and examined using FTIR and color measurements. Practical handling and performance were evaluated by varnishing two oil paintings. This study has shown that new MS3 resin demonstrates consistency with older samples of MS2A alongside improvements in keto-reduction, color, flow, and batch to batch consistency.