For your consideration are these top of the line mushroom grow bags type 4A. These small bags are 4" X 3" X 18" with gusseted sides! Small grow bags with a high filter allows you use much more substrate then most other bags available on the market. Use these bags for running spawn and get great results. The 0.5 micron filter patch allows for proper gas exchange but exclude water vapor so your spawn does not dehydrate. The filter also keeps contaminates out. Type A filtered mushroom bags are 99% efficient for gas transfer and spawn production. A bag with a Type B filter looks about the same, but the larger pore size allows breathable mushroom bags with Type B filters to be sealed before autoclaving. The material is polypropylene and is heat resistant up to 260F. Gas transmission is 1 in h2O.
Small bags are acceptable for spawn running. You will need a 8" or larger impulse sealer to properly seal these bags, however, you can get away with using paperclips or a similar device.
The uses for these bags include mushroom cultivation, mushroom spawn production, incubation of fungal products and bio-control industries
Material: 3.0 Mil Polypropylene
Bag Size: 4" X 3" X 18"
Filter Type: A
Filter Size: 1.5" X1.5"
Filter Pore Size: 0.5 microns
Filter Hole: Style L
This bag is identical to bag Type 4-B and bag Type 4-T except that it has a Type A filter.
This side gusseted breathable bag gives a sturdy stand up bag after filling and a strong bottom seal. We manufacture it with equipment we designed and with proprietary additives, These bags are pliable at any temperature as well as after sterilization. The bag opening is designed for easy sealing and the bag's bottom seal can withstand agitation.
Below is an example of a type A, 0.5 micron filter.