1 - Plain, 2 - Plain (reduced), 3 - w/ Silver Leaf, 4 - w/ Silver Leaf (reduced & encased), 5 - w/ TerraNova2 Frit, 6 - w/ Silver Glass Frit (reduced), 7 & 8 - w/ Tuxedo, Copper Green, Opal Yellow, Ivory, and Peace
Effetre Navy Blue is #591238 at Frantz which I think means that it is part of the regular production set of opaque colours from Effetre (200 series) and is machine-pulled (even number), if the way things have historically been numbered continues to carry any significance at all. This is great news for me, because I like this colour way too much to be able to cope with it going away anytime soon.
I don't want to dwell on this too much, but this colour is not really navy blue in the way that I understand navy blue should look. It is more of a dark slate blue, more on the blue side than grey. It's reactive, and it gets a really serious amount of grey scuzziness on the surface -- worse than anything you've seen with Copper Green or Dark Turquoise -- that makes the colour an excellent candidate for etching. It is probably possible to remove the dirty grey layer in other ways, but I got a new tumbler this past summer and I am pretty fixated on tumbling, so I haven't tried any of the other traditional methods like soaking Coca Cola, Toilet Bowl Cleaner, or CLR.
These beads are both plain Navy Blue, with the bead on the right having been heavily reduced. The grey smudginess is not evident in the bead on the left because this simple spacer wasn't worked much. You'll see the heavy grey sheen more visibly in the next beads since the more you work this colour, the worse it looks :)
Silver spreads out on the surface of Navy Blue and forms little silvery dots on the surface. Also, the surface of the Navy Blue has gone purplish and shiny with the addition of silver. When this is reduced and encased, it just looks like a greenish stain on the surface of the Navy Blue. Like with my Antique Green test, I'm not sure if the encased bead cracked because Navy Blue is picky about being encased or if it happened because I waited too long before I put it in the kiln. I need to do a bit more investigation here, and so do you if you want to be sure it's safe to encase it.
In my TerraNova2 frit bead, you can see that there are light halos around all of the little fritty bits. I didn't get great colour from the frit, so there's nothing magical about using it with Navy Blue, but I could probably have done better with that. The reducing silver glass on top of Navy Blue kind of blends into the background and is unremarkable in the bead on the right.
Navy Blue separates on top of Tuxedo.
On top of Navy Blue, Copper Green looks bright turquoise and separates into lighter and darker teal. Similarly, when Navy Blue is on top of Copper Green, the Navy Blue separates into lighter and darker blue.
Opal Yellow and Navy Blue aren't great together because even though there is an interesting reaction, it's polluted with a messy haze. Opal Yellow separates on top of Navy Blue and a darkish shadowy line develops around it in the Navy Blue part (see the leftmost bead). Navy Blue separates on top of Opal Yellow.
Ivory reacts dramatically with Navy Blue. You can see in the bead on the left that there is a dramatic black line reaction around the Ivory dots and lines. In the bead on the right, the Navy Blue has gone blackish mostly, but also coppery in some places on top of the Ivory. I'm not sure how to reliably reproduce that coppery reaction, but it's pretty cool.
Peace separates only very slightly on top of Navy Blue, and Navy Blue darkens around the Peace dots and lines when Peace is used on top of it. On top of Peace, Navy Blue separates and in places seems to bleed into the PEace and look a bit blurry.
And here are some fun beads using Navy Blue. All of these beads have been tumble-etched.
It's in the Rainbow cane, and used to splotch-frame the bead.
One of two base colours in this fritted cane bead set. The cane was a core of Opal Yellow encased with Navy Blue, rolled several times in my Borealis frit blend (Borealis is not yet released).
Used as the base colour in these two sets with Under the Sea FrittyBits™.
With Effetre Antique Green.
With Effetre Wood and Effetre Cinnamon Chocolotta.