Grit size is the single biggest lever over how frosted glass looks and how fast you can produce it. This page gives the reference chart, the trade-off in plain terms, and the practical rules for choosing and changing grit.
Grit size reference chart
Abrasive grit for glass sandblasting is graded by mesh number. Higher number means smaller particle. The chart below covers the grades we stock, with approximate median particle size under the FEPA F designation.
| Grit | Approx. median particle size | Character of the frost | Typical use on glass |
|---|---|---|---|
| 24# | ~685 µm | Very coarse, strongly granular | Deep carving, heavy texture, aggressive stock removal |
| 30# | ~580 µm | Coarse | Deep carving, multi-stage blasting |
| 36# | ~485 µm | Coarse | Heavy texture work, first-stage passes |
| 46# | ~370 µm | Medium-coarse | Textured decorative surfaces |
| 60# | ~260 µm | Medium | General decorative work; a common working default |
| 80# | ~185 µm | Medium-fine | Frosting with visible but even texture |
| 90# | ~155 µm | Fine | Uniform frosting, general architectural glass |
| 100# | ~129 µm | Fine | Smooth, milky frost; premium architectural finishes |
| 120# | ~109 µm | Very fine | Finest uniform frost, detail work, close-viewed surfaces |
Particle sizes are approximate median values for FEPA F-graded material and are given for comparison between grades. Any graded abrasive is a distribution, not a single particle size.
The trade-off, stated plainly
It is consistent and predictable in both directions:
- Coarser grit cuts faster and removes more material per pass. The result is a rougher, more granular frost. Better for speed and for deep carving.
- Finer grit cuts more slowly but leaves a smoother, more uniform, more “milky” frost. Preferred where the surface is viewed up close.
There is no free lunch here. If you want a premium smooth finish, you accept slower cycle times. If you want throughput, you accept visible texture. The skill is knowing which one your customer is actually paying for.
How to choose for your product
Architectural glass viewed up close
Shower enclosures, partitions, interior doors, mirrors. People stand within a metre of these surfaces and run their hands over them. Go finer — 90# to 120#. The uniformity is the product.
General decorative and patterned work
Logos, borders, patterns cut from masking film. 60# to 90# is the usual working band. Fine enough to look deliberate, fast enough to be profitable.
Deep carving and heavy texture
Where you are removing real depth rather than just fogging the surface. 24# to 46#. Some shops run a coarse first stage for depth and a finer second stage to clean up the surface character.
Signage and exterior glass
Usually viewed from further away, so texture matters less than contrast and durability. Mid-range grit is generally sufficient — do not pay in cycle time for a finish nobody sees.
Grit size and masking film have to be chosen together
Coarse abrasive at high pressure attacks the mask as well as the glass. If your stencil is breaking down or the pattern edges are ragged, the cause is often a grit-and-film mismatch rather than a bad film.
As a rule: the coarser the grit and the longer the blast, the thicker the film you need. Fine detail wants thinner film for a cleaner cut and a sharper edge. The full thickness breakdown is in the masking film thickness guide.
Changing grit costs more than you think
Switching grit means purging the machine — recovering what is in circulation, clearing the recovery system, and charging fresh media. It is not a five-minute job.
The practical consequence: most production shops standardise on one grit for their main product and keep a second on hand for special work, rather than switching per job. Deciding your default properly is worth more than the flexibility of switching freely.
If you find yourself changing grit more than occasionally, the real problem is usually that you have said yes to two products that want different machines.
Recycling: grit does not stay the same size
Production abrasive is recovered, separated from dust and fines, and reused many times. That is what makes the cost per panel reasonable rather than the cost per bag.
But particles round off with each cycle. A rounded particle cuts more slowly and produces a slightly different surface character than fresh angular media. Brown fused alumina holds up well here because it fractures into fresh cutting edges as it degrades rather than simply polishing smooth.
Practical indicator: when cycle times start creeping up at unchanged pressure and settings, your media is spent. Top up or replace rather than compensating by raising pressure — raising pressure to rescue tired abrasive is how people damage masks and accelerate nozzle wear.
Grit is one of three variables
Grit size does not act alone. The finish you get is determined by three things together:
| Variable | Effect |
|---|---|
| Grit size | Particle size, and therefore texture scale |
| Working pressure | How hard each particle strikes; our machines run 0.6–0.8 MPa |
| Travel speed | How long any point on the glass is exposed |
Changing any one changes the result. This is why a grit chart is a starting point, not a recipe — see air pressure and nozzle settings for how the other two interact.
Always confirm on a test panel
Any number on this page is a starting point for your machine, your air supply, and your glass. Run a test panel before committing a production batch. Frosted glass is unforgiving — you cannot un-blast a panel.
Getting the right abrasive
Tell us the finish you are trying to achieve and the machine you run, and we will recommend a grit rather than let you buy a range and guess. See abrasive options or request a quote. We usually reply within one business day.