Logarithm of the production rate and dust-to-gas ratios of comet 46P with respect to CN (Log10[Q(xx)/Q(CN)]) and to OH (Log10[Q(xx)/Q(OH)]) as a function of time to perihelion. Pre-perihelion values are represented with open circles and post-perihelion values with filled circles. The dust-to-gas ratio is expressed in cm second per molecule. The horizontal dashed line indicates the mean ratios of typical comets given in Schleicher (2008).