Clear Reichenbach powder—or any clear glass powder—can turn white, milky, or cloudy after fusing for a few reasons.

1. Micro-bubbles trapped between the tiny particles

When you sift or layer clear powder, the tiny grains trap a LOT of air.
 When it fires, that air expands and forms micro-bubbles, creating the appearance of:
·      White haze
·      Frostiness
·      Cloudy or devitrified look
This is the number one reason clear powders look white.
The more powder you use, the whiter it looks

2. High surface-area = higher risk of devitrification

Powder has the highest surface area of any glass form, which means:
·      It picks up contaminants easily (even from the air)
·      It encourages crystal formation on the surface
·      It devitrifies more easily than frit, sheet, or rod
Devit looks exactly like a white matte scum layer.

Here’s what’s going on and how to minimise it
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Why Reichenbach Crystal Clear goes white.

1. Micro-devitrification (the big one)

Reichenbach clears are more devit-prone than Bullseye or Oceanside clears.

When held too long between ~650–800 °C (1200–1470 °F) or when heated slowly through that range, or when used as powder/fine frit.

→ the glass surface starts to crystallise, creating a milky or cloudy white haze.

This is devit, not dirt.

2. Powder & fine frit exaggerate the problem

If you’re using: Reichenbach clear powder or fine frit as a dusting or cap
You massively increase surface area → much higher devit risk. That’s why it often looks: White Chalky or like it’s been “etched”.

3. Incompatible firing style

Reichenbach clears don’t love: Long bubble-squeezes, slow ramps into top temp, extended holds at tack fuse temps, they prefer decisive, hotter, cleaner firings.

4. Reaction with sulphur/opal whites (occasionally)

Less common, but some opal whites (especially sulphur-bearing)
Can exaggerate clouding at the interface
This usually shows as edge haze, not full whitening.

How to reduce or prevent it 

Fire hotter, faster, shorterInstead of creeping up slowly: Move quickly through 650–800 °C. Go to a slightly hotter top tempHold shorter, not longer. Devit loves slow, gentle schedules. 

Cap with a different colour. Best practice: Use Reichenbach clear inside cap with: Bullseye Tekta Oceanside Clear, Bullseye Crystal Clear. That outer clear protects against devit and fires cleaner. 

Avoid clear powder on the surface. If you need a dusting, use very sparingly or switch to Bullseye clear powder for surface effects.

Fire-polish can sometimes save it. If the haze is light: A hot, fast fire-polish can re-melt the devit layerIf it’s heavy devit → it usually won’t fully clear.

Devit spray (last resort). Sprays like Hotline or Fuse Master can help prevent devit. Rarely fix it once it’s already there.

Over-firing or holding too long near 700–750°C

Reichenbach and the other 96 COE clears can devitrify if exposed too long to:

·      680–760°C (slow ramps, long soaks)
·      Heatwork from multiple firings

Tack fuses are actually riskier than full fuses because the glass spends longer in the danger zone.

What can you do to prevent the white haze?

A. Use less powder
Thin, even dusting instead of a thick layer.
Thick powder layers always look white.

B. Cap the clear powder
If you need true optical clear, powder under a cap sheet gives vastly better clarity.

C. Fire hotter + shorter
A schedule like this helps:

149°C/hr to 675°C – no hold  
333°C/hr to 805°C – hold 10 minutes  
Full to 482°C – hold 60 minutes  
83°C/hr to 371°C – off
Higher top temp + fast heating decreases devit.

D. Consider switching to frit
Clear frit (#1 or #2) stays clear.