FACE SIDE:
Side of a double-face tape that is unlined.

FALL OFF:
Complete pulling away or dropping off from the surface that the tape has been applied.

FEATHERING:
An irregular paint line after seepage has occurred under a masking tape.

FIBER:
A thread-like material giving texture or substance. Can also be spun or woven.

FILAMENTS:
Threads of rayon, polyester or glass laminated to backings to produce very strong tapes.

FILLER:
A substance added to an adhesive to improve its strength, working properties, permanence or appearance.

FIRM:
Referring to the resistance of an adhesive to flow.

FISHEYES:
When observed on a roll of transparent tape this is the appearance of the adhesive surface. Caused by the entrapment of air between layers on the roll, this is not indicative of poor tape, but is generally found in new or very fresh tape. Loses this appearance during storage.

FLAGGING:
When the end of a piece of tape comes away from the object it was intended to adhere to. This is usually applied to plastic tapes if they spring up. See - Curling, Dead Stretch, Elastic Memory, Lifting.

FLAKING:
During tape removal the breaking off or flaking of paint from a masking tape backing.

FLAME-RESISTANCE:
The ability of a tape to withstand exposure to flame. Fireproof materials will not burn when exposed to flame. Flame resistant (fire retardant, self-extinguishing) materials will burn when exposed to flame but will not continue to burn after flame is removed.

FLAME-RETARDANT:
Materials that resist burning.

FLASH POINT:
The minimum temperature of a liquid at which its vapor will form a mixture that will burn.

FLAT BACK PAPER:
A term used to describe a smooth paper backing for a tape to distinguish it from creped paper backings.

FLEXIBILITY:
The ability of a tape to be freely bent or flexed during application. Particularly applicable in low temperature use.

FLEXURAL STRENGTH:
Maximum stress that a material can withstand when flexed or bent before it breaks.

FOAM:
Material formed by creating bubbles in a base material.

FOIL:
Thin flexible metal, such as copper foil or aluminum.