Both cut glass. Both are used in production frosting every day. The choice is not about which is better — it is about which trade-off suits your shop.
Here is the honest comparison, including where garnet wins and where it does not.
Side by side
| Brown fused alumina | Garnet | |
|---|---|---|
| Origin | Manufactured — bauxite fused in an electric arc furnace | Natural mineral, mined and graded |
| Relative hardness | Harder | Softer |
| Particle shape | Angular, sharp | Angular but less aggressive |
| Cutting speed on glass | Faster | Slower |
| Behaviour as it breaks down | Fractures into fresh cutting edges | Breaks down more readily into fines |
| Recycling life | Longer — the main economic argument | Shorter |
| Dust generated | Higher | Generally lower |
| Surface character | Crisper, more aggressive texture | Slightly softer surface character |
| Cost per bag | Higher | Lower |
| Cost per panel in a recycling system | Usually lower | Usually higher |
Why alumina dominates production frosting
The decisive property is not hardness — it is how the abrasive behaves as it wears.
Brown fused alumina is friable in a useful way. As particles break under impact, they fracture along crystal planes and expose new sharp edges rather than simply rounding off. In a recycling system that means the media keeps cutting through many cycles instead of gradually turning into expensive sand.
That is why the cost per bag is misleading. A shop comparing bag prices will pick garnet. A shop comparing cost per square metre of finished glass usually picks alumina, because the alumina charge lasts substantially longer in circulation.
If you run a recovery and separation system — and any production shop should — compare cost per panel, not cost per bag. It frequently reverses the answer.
Where garnet is the better choice
Garnet is not a budget compromise. There are real cases where it is the right call.
Dust control
Garnet generally generates less airborne dust in use. If your dust collection is at its limit, if your facility has tight air-quality constraints, or if operator comfort is a live issue, this can matter more than cutting speed.
Surface character
Some shops prefer the finish garnet produces on certain glass — slightly softer in character than alumina at equivalent grit. Whether that reads as “better” depends entirely on what your customer is buying. This is a genuinely subjective judgement and worth testing rather than arguing about.
Non-recycling or low-volume operations
If you are not recovering and reusing media, alumina’s recycling advantage is worth nothing to you and the lower purchase price of garnet becomes the relevant number.
Customer or specification requirements
Some architectural specifications name a media type. If your customer specifies it, that settles it.
The decision, condensed
| Your situation | Likely choice |
|---|---|
| Production frosting with abrasive recovery | Brown fused alumina |
| Dust control is a binding constraint | Garnet |
| High throughput, cost per panel matters | Brown fused alumina |
| Low volume, no recovery system | Garnet |
| Deep carving, aggressive material removal | Brown fused alumina |
| A specific surface character your customer buys | Test both |
| Specification names a media | Follow the specification |
What does not change between them
Both are supplied across the same grit range — 24#, 30#, 36#, 46#, 60#, 80#, 90#, 100#, 120#. Grit selection follows the same logic for either media: coarser cuts faster and rougher, finer cuts slower and smoother. See the grit size chart.
Both work in vertical and horizontal machines, at the same 0.6–0.8 MPa working range. Neither requires a different masking film, though a faster-cutting media at the same settings does ask slightly more of the mask over a given cycle.
Do not run both without a reason
Mixing media in one recovery system is a bad idea — different densities and breakdown rates make separation and consistency unpredictable. Switching between them means purging the machine.
The practical implication is the same as with grit: pick one as your production default and change only for a deliberate reason. Shops that keep both are usually running genuinely different product lines, not hedging.
How to decide without guessing
The honest answer is that surface character is subjective and dust tolerance is site-specific, so a table can only take you so far. Blast a test panel with each at your working grit and pressure, put them side by side, and look at them the way your customer will.
Tell us the finish you are trying to achieve and the machine you run, and we will recommend one rather than let you buy both and guess.
See abrasive specifications or request a quote. We usually reply within one business day.