From L to R we have Bloom London, Glitter Gal (Sparkle) Black, BK 02, Catherine Arley 805 and Economy Class (my MPJ franken)
I made the franken about a year ago and sent some over to a friend with the original charcoal MPJ and she confirmed they were dupes in terms of colour and holoness except mine was a little more opaque. I've since added just a touch of clear to get an exact dupe.
Also, I decided not to include ChG Let's Do It In 3-D, CC Revvvolution etc because I felt they weren't dark enough to be considered black.
Anyway, enough jabbering from me...
I've kept the pics extra large so click for a lot more detail. This is 2 coats of each except for the MPJ franken which is 3 coats.
You can see here that the first two, Bloom London and Glitter Gal Black are scattered holos while the other three are linear.
At first I thought these two were dupes. But as you can see, the Glitter Gal is clearly more holo- the particles in it seem to reflect a more distinct rainbow than the Bloom which is really, really weak.
Out of these three, the least holo was Catherine Arley 805. The holo effect in this one seemed a little less pronounced and it mostly reflected red/orange/yellow instead of the full rainbow.
The other two (BK 02 and my MPJ franken) are very similar except the BK is almost opaque in one coat while my MPJ franken requires at least three. Also, the base colour of the BK is very obviously black while the franken leans charcoal.
After I did this comparison I decided to do my nails in BK 02.
Can you see a corner of my middle nail broke off? It's too low down to make all my nails that length :( Oh well, what can you do.
Hope you enjoyed!