Re: defining media white
Re: defining media white
- Subject: Re: defining media white
- From: Greg Nuckolls <email@hidden>
- Date: Tue, 2 Oct 2001 13:49:27 -0500
There are actually two measurements... Whiteness and Brightness. Whiteness
is a measurement of Color, using a CIE scale and standards. Brightness (the
number commonly seen on paper packaging) is a measurement of the reflectance
of the paper at a 45 degree angle, in blue light (457nm).
Specifically (from a paper manufacturer's site), "Brightness is the amount
of light reflected by the paper expressed as a percentage. The Technical
Association of the Pulp and Paper Industry, or TAPPI, defines brightness as
the 45-degree directional reflectance at 457 nanometers. A brightness rating
of 85 means that 85% of the light spectrum is reflecting at 457 nanometers."
GE Brightness is a commonly seen term; GE was the original manufacturer of
equipment for this testing.
Offshore manufacturers use the ISO scale, which differs slightly. For more
info on these, see ISO 2469 and ISO 2470. www.tappi.org ; www.iso.org
Hope this helps...
Greg Nuckolls
Color Analyst
A&E Products Co., LP
"Reprographics With A CAN-DO Attitude!"
www.aeproducts.com