Mayco · Stoneware SW-402
Dark Flux
$22.00
Pint · yours to keep · no up-charge, any membership level
Chemically Light Flux’s twin, visually its opposite. Translucent brown on its own, so everywhere it thins out over a rim or a throwing ring you get a warm dark line, and everywhere it pools you get depth the glaze underneath could never produce alone. This is the bottle for a piece that came out pretty but reads flat.
How you get it: show your receipt to one of our main instructors and they’ll grab you your bottle.
- Fires atCone 5–10
- SizePint
- Apply2 to 3 coats
- Food surfacesNon-toxic, dinnerware safe
Using it
Treat it as shadow, not as paint.
Dark Flux is the one bottle here that rewards restraint. It is a translucent brown, so the more of the pot you cover, the closer you get to simply painting the whole thing brown. Used on part of a piece it does something no other glaze on our wall does.
Two to three coats
One coat will change the color of what it touches but barely move it at all. Two to three is where the flowing, pooling behavior you are buying this for actually starts.
Thin it out as you go down
We recommend going thinner the closer you get to the bottom. Mayco says the same thing their way: to prevent run-off, keep flux off the bottom third of the ware.
Partial application is the move
Brushed on the top third of a mug it gives you a warm dark rim fading into clean color. That is a legitimate technique, not a shortcut, and it usually beats covering the whole piece.
Test where it cannot hurt you
Mayco’s own recommendation is to try a new combination inside a piece, or on a cookie. When the people who made it assume you will have a run, believe them.
How far down should it go?
This is the decision that costs you time later. The closer to the bottom you take it, the more of it drips into your catcher — which usually means a lot more grinding afterward. It is also, deliberately, where a lot of the beauty comes from.
About a third of the way down
Leaves two thirds of the clay naked. Usually beautiful, the least grinding of the three, and the sweet spot for this particular bottle.
About two thirds of the way down
The other line that tends to look right. More brown, more movement, a strip of naked clay at the foot, and more drips reaching the catcher.
All the way down
Maximum movement and maximum cleanup, and the highest chance the piece just reads brown. If you go this far, make sure the glaze underneath is pale enough to fight back.
Vertical walls move dramatically more than flat surfaces. The same combination inside a bowl and on the side of a mug is effectively two different experiments.
Six starting points
What to put it with.
Dark Flux wants something pale underneath it. Mayco built the fluxes to layer with their own Stoneware glazes and with Stroke & Coat, but the rule that matters here is contrast. These are researched starting points, not tiles fired in our kilns. Test first, then tell us how it went.
Over Birch
Flux on top · 2 coatsCreamy off-white with warm brown rivulets running through it. This is the fix for a piece that came out pretty but flat, and the most forgiving thing on this list.
Over Vanilla Dip
Flux on top third only · 2 coatsVanilla with a burnt edge. Brushed only on the top third it gives a warm dark rim that fades into clean cream, which suits a mug better than almost anything else here.
Over Alabaster
Flux on top · 2 coatsA pale matte gains a glossy amber-brown wash that settles into every throwing line and every thumbprint. Expect the matte surface to become satin or glossy in the process.
Under Sandstone Shino
Flux underneath · 2 coatsUnderneath a shino, the brown deepens the break so the surface reads older and more weathered without the glaze visibly running anywhere. The safest thing on this page.
Over Seafoam
Flux on top · 2 coatsPale green with brown breaking through it, somewhere between celadon and old bronze. Brown over green is one of the oldest good ideas in ceramics.
Over Micro Pearl
Flux on top · 2 coatsThe dramatic one on this list. A pale pearly Classic is already a lively glaze, so adding brown melter on top gives you bronze streaking and heavy pooling — and a genuine chance of reaching the shelf.
Sixteen more combinations across all four fluxes are on the flux collection page, and every glaze named here is in the Glaze Bible.
Plan it before you brush it
Where it sits, and how much it will run.
Under, over or sandwiched
The dramatic one
The brown melts on top and runs downward. Everywhere it thins over a rim or a throwing ring you get a warm dark line, and everywhere it gathers you get real depth. The pale glaze underneath supplies the contrast that makes all of it visible.
Best over: Birch, Vanilla Dip, Alabaster — pale glazes that currently read flat.
Underneath is the underused option with this bottle. It buys you depth with almost none of the run risk.
How much will it run?
Moderate run risk
Expect real movement and some visible travel down the wall. Thin your coats as you get closer to the bottom.
Glaze catcher required. There is flux on the outside of this piece, so it goes into the kiln on a catcher you supply. No exceptions, at any height.
The one rule
Dark Flux on the outside means a glaze catcher.
Any pottery with Dark Flux applied to the exterior must go into the kiln sitting on a glaze catcher that you supply. Every piece, at any height, no exceptions.
Members are financially responsible for any damage to kiln shelves, and for the wages I pay my studio manager to fix the problem. Just don’t do it. Not to mention, glazes running onto shelves destroy your pot too.
A catcher protects the shelf and the studio — it does not save the pot. Once glaze has run off the foot you have a hard ring of glass on the bottom and a grinder in your future. The further down the pot you took the flux, the more of that there will be.
Before you commit a good pot to it
Where Dark Flux disappoints people.
Over a dark glaze it is wasted
You spent $22 to make something slightly darker. Dark Flux only shows up when there is something pale underneath for it to break against.
It eats bright colors
Oranges, reds and hot pinks go first. If the color is the point of the piece, this bottle is working against you — reach for Light Flux instead.
Flood it and it reads muddy
Covering an entire pot in a translucent brown is not layering, it is painting it brown. This glaze does its best work as an accent on part of a piece.
It turns matte glazes glossy
Same family trait as Light Flux. If you picked a matte for the way it feels in the hand, Dark Flux deletes that decision.
One coat does nothing
A single coat shifts the color and leaves the mobility more or less alone. Two to three is where the behavior starts.
Rough is not a food surface
Mayco rates it non-toxic and dinnerware safe, and we are fine with it inside a mug or bowl. But layered glazes sometimes come out rough or pitted, and rough traps food. If it comes out textured, keep that piece decorative.
How it compares to the other three
Honey Flux
$26 · Amaco PC-17
Amber and cream. The one for dark iron glazes, and the only one that changes identity between cone 5 and cone 6.
Light Flux
$22 · Mayco SW-401
The same chemistry as this bottle, translucent cream instead of brown. Pick it when the color is already right and you only want movement.
Dark Flux
$22 · Mayco SW-402
Translucent brown. Shadow, depth and a warm dark edge on any pale glaze that currently reads flat.
Running Hot Chowder
$21 · Spectrum 1173
Creamy and glossy, and a complete glaze on its own. Pick it for carved texture, where it floods the cuts and thins on the ridges.