Rosin Bag Micron Sizes Explained: How to Choose the Right One

When it comes to solventless extraction, every detail matters, from your starting material to your press temperature. But one of the most overlooked factors in producing clean, high-quality rosin is the micron size of your rosin bag.

If you’ve ever wondered what those numbers mean — 25, 37, 90 — this guide breaks it all down so you can choose the right micron for your next press and get the best balance of purity, flavour, and yield.

What Is a Micron?

A micron is short for “micrometre,” equal to one-thousandth of a millimetre (0.001 mm). In the world of extraction, micron size refers to the size of the mesh holes in your rosin bag.

The smaller the micron number, the tighter the weave, meaning it will filter out more unwanted plant material and allow less oil to pass through. A larger micron number allows for greater flow and typically higher yields, but with more impurities in the final product.

Common Micron Sizes and What They’re Best For

25 Micron – Ultra-Fine Purity

This is the tightest filter size most extractors use. A 25-micron bag captures nearly everything except the purest oil.
Best for:

• • Ice-water hash or bubble hash rosin
    
  • Small-batch or high-quality material
    
  • Maximum clarity and purity (lowest yield)
    

37 Micron – Balanced Performance

The 37-micron bag is the all-around favourite. It provides a near-perfect balance between filtration and flow.
Best for:

• • Dry sift or high-end flower
  • Consistent results with good clarity and flavour
  • Those seeking both purity and efficiency
    

90 Micron – High Yield Flow

The 90-micron bag has a much wider mesh, allowing more oils and plant compounds to pass through for higher yields.
Best for:

• • Pressing flower rosin
    
  • Larger volume or faster extractions
    
  • Maximising yield while keeping strong terpene content
    

How to Choose the Right Micron Size

Selecting the right micron bag depends on your starting material and end goal:

• • Bubble Hash / Ice Water Hash: Use 25–37 micron bags for the cleanest results.
    
  • Dry Sift or Kief: Stick with 37–73 micron.
    
  • Flower Rosin: Use 73–120 micron, with 90 micron being a sweet spot for most users.
    

Pro tip: Smaller micron = cleaner output, larger micron = bigger yield. Find the balance that suits your material and expectations.

Extra Pressing Tips

• • Use a quality press — consistent pressure and heat are essential for clean, even extractions. Clearly Gold Presses offer reliable performance in two sizes: the GS Lite 10 Ton for full-capacity control and the Mini Squish 4 Ton for portable, small-batch pressing.
  • Pre-press your material into uniform pucks to prevent blowouts.
    
  • Don’t overfill bags — leave room for expansion.
    
  • Press slowly and let the oil flow at its own pace.
    
  • Lower temperatures (170–190°F) = more flavour and clarity.
    
  • Higher temperatures (200–220°F) = higher yield but darker rosin.
    

Make It Monday at The Next Level

Every Monday, we make extraction easy with 10% off select extraction tools and supplies, including rosin bags in 25, 37, and 90 micron. Whether you’re pressing bubble hash, kief, or flower, we’ve got the gear to help you level up your results.