Dichroic filters are durable glass color filters that transmit only certain wavelengths of light, reflecting the rest of the spectrum, rather than absorbing it. Since virtually no energy is absorbed by the filter, light transmission is significantly higher than traditional gels and will never burn out or fade.
The gel equivalent to Rosco's "Three Quarters CTO" Dichroic Filter is Roscolux 3411.
Rosco Architectural Series Colors has been designed with the assistance of architectural lighting designers around the world and is perfect for both interior and exterior architectural lighting projects. Subtle, pale color tints are perfect for accent lighting and offer a unique alternative to the typical bright saturated colors available from other dichroic suppliers.
Permacolor filters are manufactured in five standard sizes on durable borafloat glass 1.75mm (.069") thick or can be custom cut in any size up to 13.5" in diameter.