Michael Miller jet black is my favorate - it has a softer "hand" then the Kona black - I quess it would depend on the hand feel of your other fabrics and of course MM jet black cost more then Kona.

You might want to make sure you wash a piece of the black before using it -- this will give you an idea if the color bleeds and if the fabric will gray a bit once it is washed. I like the Michael Miller and Maywood studios black. Yes, be sure you buy enough to finish the project -- some blacks have a blue cast, some are a bit gray and some a red cast and you don't want them side by side.

Michael Miller's Jet Black is the blackest black, and I think it remains true through washings. I haven't washed mine yet, so don't know that for a fact.

If you can, it would be great to buy half a yard of several blacks and test. Come to think of it, maybe I will do that at some point in the future. I would cut each one in half, label each (maybe with white embroidery?), then wash one half of each manufacturer under harsh conditions in the washing machine, afterwards comparing the washed half with the new half to see if color is retained well.

Edit: I should add that I have used Kaufman Kona black and find the hand to be unusually coarse -- sort of thick and meaty, and I found that the edges of strips seem to fray frantically. The Michael Miller Jet Black that I have has a much nicer hand and did not fray like the Kona. I do believe the Kona is sure to retain its color, however.

My preference is 5 or 6 blacks, or 20 blacks :) helps the eye move across the surface and adds interest. And there is zero chance of running out of a fabric.

Kona black is one of the truest black and is most used by Amish..

Yes the Amish black at Keepsake is beautiful fabric. Only black I ever use.

Kona black is the one we sell at the shop.

Eclipse by Blank Quilting. Jet Black. Dyed to be a true black. Put it up against other black fabrics, it passes every time! I buy it by the bolt.
Sandy

I buy kona black and snow by the bolt when Hancocks of Paducah has free shipping. If you buy 15 yards (size of bolt) you get additional discount.

I've only used Kona Black and very happy with the quality. Haven't had a problem with fading onto other fabrics. I agree with ArtsyOne, be sure and purchaset the amount you need from the same bolt.