I have a two part question that relates to printing on VC paper using subractive color heads. PART A: These color heads have YELLOW, MAGENTA, and CYAN filters that can be inserted into the white light stream in varying degrees from "0" to "200" color units. At least, that's the range of color units on my Beseler 45s. How consistent are these color units from one head to another? If I change heads, or even brands of heads, can I expect to obtain the same printing color of light (i.e. the same paper contrast) by dialing in the same color units on the new head as on the previous head? I keep good notes on how I print a given negative. I want to reproduce the same print later and have it look like the print I used to write the notes. PART B: Does it make sense to use a color analyzer and record the color for a given negative, and for future reference in that regard? So, if one changes a head or brand, then in theory, one could always get back to the original color with a different enlarger head? I ask these questions, because I've not used a color head for VC printing, and I've not used a color analyzer.