QUATREFOIL, in Gothic architecture, the piercing of tracery in a window or balustrade with small semicircular openings known as "foils"; the intersection of these foils is termed the cusp.
This is achieved by the quick changeover of hot stamping foils, which in many cases are used for relatively small runs.
Holograms or holographic foils are standard means of overt consumer assurance of authenticity.
The thermal neutron fluence rate can be measured at the customer?s premises using gold foils as the transfer standard.
gold foils as the transfer standard.