GROWLAY properties:

• GROWLAY is microcapillary. Its cavities absorb and store water, dissolved liquid nutrients or fertilizer. Promoted because of the capillary action throughout the printed object.
• Mold grows through the open-cell capillaries and forms a mycelium.
• Seeds of grasses can get caught and grow in Growlay.
• Spores find room to germinate in small cavities. (see SEM-Pics)
• Roots cling to the structures of the object filling.
• Even lichens grow on Growlay. These usually grow preferentially on stones of walls or trees.
• GROWLAY can be sterilized (for food use and research) with gases or wet (but not thermally)
• For colour differentiation, objects printed with Growlay can be subsequently coloured with food colours.
• Is an absorptive carrier for agents

GROWLAY is available in the functionally different versions white and brown
Version white is an experimental filament & fully compostable
The brown version contains not only pores but also built-in "food" in the form of cell material which is needed for growth

PLEASE NOTE:  GROWLAY - has two versions:

1) GROWLAY-WHITE, pure & porous, experimental filament for experienced users only

• Fully Compostable polymer
• With open capillaries
• White filament
• Print range from: 85° - 135°C
• GROWLAY-white 1.75mm (real: 1.55mm - 1.85mm)

PLEASE NOTE !

• As a beta version 1.75mm Growlay filament comes unfortunately in variation of diameter from ~1.45mm to 1.8mm
• Is not as easy to print with Bowden extruders
• Filament can be fast grinded at the hobbed bolt if the feed somewhere is blocked
• The 3mm filament prints a little easier due to its thickness 
• GROWLAY-white 3.0 mm (real average: 2.50mm – 2.85mm) works fine, also with Bowden

2) GROWLAY-brown, porous + wood particles, for any user

• Not compostable
• With open capillaries
• Polymer contains organic nutrients (+wood particles)
• Higher tensile strength
• More rigid as version white-
• Increased temperature stability
• The filament can be printed just as easily as Laywood,
• Brown filament
• Print at: 235°-250°C

https://www.3ders.org/articles/20180702-kai-parthy-launches-new-bio-degradable-growlay-3d-printing-filament-for-indoor-farming.htm