STFI is a German association which produces STFI abrasive fabric.
This abrasive fabric complies with DIN ISO 12947, amongst other standards.
James Heal’s SM25 also complies with DIN ISO 12947, therefore from a Technical perspective, the two products are the equivalent of each other.
James Heal’s SM25 can be used as a substitute abrasive fabric unless the standard does not allow it and states that STFI must be used.
James Heal is unable to supply STFI abrasive fabric as the manufacturer only sells directly to customers.
A PDF version of this FAQ is available for reference.