Two things here. First we do need to over expose the negative relative to the required exposure for silver gelatin prints since alt. process prints typically have a longer toe than silver gelatin does. This causes negatives created for silver gelatin to have very muddy low tones with little seperation in those values. Then we also need to increase development to produce a negative with the appropriate density range for the specific process.
Originally Posted by buggy
One other thing to think about, VDB has a signifigant dry down. If you don't tone your prints before fixing you can bleach the print using the bleaching formula listed in Wynn White's VDB article found on the Unblinkingeye.com. Of course this is one of the advantages using a digitally enlarged negative since dry down is built into the calibration process. Of course in camera negatives can make great prints also.