The short answer
Run your screens from coarse to fine and expect three working grades. A 150 to 220 micron screen breaks up the material and catches stalks and leaf bits. A 90 to 125 micron screen collects the grade most makers keep as their head stash. A 45 to 73 micron screen pulls a fine powder that clumps fast and needs a light touch. Going below 45 micron usually means you are sifting more plant matter than resin, so most home setups stop there.
What each micron band collects
- 220 to 150 micron: the work screen. Breaks apart flower and trim, holds back stems, fan leaf, and large debris.
- 150 to 120 micron: a transitional grade. Cleaner than the work screen, still carries some stalk fragments.
- 120 to 90 micron: the sweet spot for most dry sift. Resin heads pass, most contaminant stays behind.
- 90 to 73 micron: finer grade for blending or pressing. Smaller yield, higher purity.
- 73 to 45 micron: powdery and static prone. Handle with a cold card and minimal pressure.
- Below 45 micron: mostly dust and ruptured heads unless your starting material is exceptional.
Micron ratings describe the opening size. Mesh counts describe threads per inch. Do not swap the two numbers when you buy screens, because the same opening can carry a different mesh count from one supplier to the next.
Prerequisites
- Dry, cured flower or trim. Moisture makes resin smear instead of fall.
- A cold room or a chilled work surface, ideally 60 to 65 F and low humidity.
- A stacked screen set with rigid frames and a catch tray.
- Parchment paper, a clean collection card, and nitrile gloves.
- A soft bristle brush reserved for resin only.
How to run a screen set
- Chill the material and the screens for at least 30 minutes before you start.
- Place the coarsest screen on top of the stack and the finest screen at the bottom over the catch tray.
- Load a small handful of material onto the top screen. Keep the layer thin.
- Move the material in slow circles with a gloved hand or a soft card.
- Stop as soon as the falling powder turns from pale gold to green or brown.
- Lift the top screen and set it aside. Move the material from the second screen onto the third.
- Repeat the gentle circle motion on each remaining screen.
- Scrape each grade onto separate parchment and label it with the micron size.
- Clean the screens with the soft brush, then store them flat and dry.
Reading your results
A pale, sandy grade that stays loose at room temperature is a sign your material was dry enough and your motion was gentle. A sticky grade that darkens within minutes means you pushed too hard, worked too warm, or started with material that was not fully cured. If the 90 micron screen is producing green powder, back off the pressure and shorten the run instead of buying a finer screen.
Cleaning and storage
Keep each grade in its own glass jar, sealed and out of light. Dry sift degrades faster than whole flower because the surface area is huge. Store jars cold, let them come to room temperature before opening, and avoid stirring the contents. Clean screens last longer and sift cleaner, so brush them after every session and never wash them with water.