Archival ink is specifically designed to be resistant to weathering and fading so that it will last for a long time. It is often used for scrap-booking and other activities where the written or drawn images need to be preserved indefinitely. To make the most of archival ink, it is best to use it in conjunction with archival paper, which is also made to resist weathering and fading. Archival ink is often sold through art supply stores. You can find it sold as ink, in archival pens and, in some instances, in printer cartridges used by photographers.
To be designated as archival grade ink, the ink must demonstrate two things: the ability to resist fading, and the ability to remain firmly on the page. With the passage of time, normal ink will begin to fade. Most black ink will turn brown, first, before completely disappearing from the page. Exposure to moisture can also wash out the ink, leaving it blurry, smeared or completely erased. By changing the chemical composition of the ink, these two factors are no longer a concern to the archivist.
Most archival inks could really be best described as dyes, in that they permanently change the color of the paper that is being used. Dye is more likely to remain colorfast to the extent that the dye’s components are colorfast. Pigment is an even more reliable component of archival ink, because it stays bright and durable as well as colorfast. This makes pigments popular for use in archival pens, inks and printer cartridges.