Archival printing: Definition of jargon

[Sanford]

When a printer manufacturer states it's prints have a life of 80

years does this mean after 40 years the print is half gone or the

fading starts after 80 years?

[kevinteo]

Light fastness tests are accelerated simulations in a print is

subjected to exposure to light of different intensities (usually one

to measure the actual light fastness, and the other as a control

against reciprocity failure) until certain conditions are met.

 

Generally, these standards are:

 

- 30% change in neutral patches

 

- 30% change in color patches

 

- 15% change in color balance of neutral patches

 

- 0.10 change in D-min

 

- 0.06 change in color balance in D-min

 

When this conditions are met, the time taken is scaled

accordingly to real time. So when a print has a rated life of 80

years, it means that after 80 years, the above five things would

have taken place.

[kevinteo]

The loss of ink intensity that results in the changes I mentioned

above is measured with a densitometer. The conditions above

also mean that fading alone isn't the only factor, paper turning

yellow for example, can also cause a color shift, or a change in

D-min.

 

Hope this was helpful.

[kelly_flanigan1]

In printing; the colors will fade at different rates due to UV exposure. A color wheel exposed in direct sunlight will have it's red colors fade first.

[neil]

Does it mean "all" of the above things, or "one or more" of the above things would have taken place?