Polarization monitoring as a probe of blazar jets on the finest scales

Polarization variability combined with imaging in total and polarized intensity and multi-waveband flux monitoring can identify which regions in the jets of blazars produce the optical to gamma-ray emission. Here we present evidence that the fluctuating high frequency components are co-spatial with the millimeter-wave jet as seen on VLBI images on scales less than I milliarcsecond. Using currently available and future instruments, we plan to use polarization to explore the link between high and low frequency emission processes in blazars.