The 25-pack antique white 11 x 17" 2-Ply 100% Cotton Museum Board from Archival Methods is suitable for matting, mounting, and preserving valuable documents, fine prints, and photographs. When used for window mats and mat backing for small prints, the 2-ply thickness of each museum board provides a 1/32" separation between artwork and glazing, thus providing flat and sturdy support. Made of 100% cotton fiber without any brightening agents, this museum board is acid and lignin-free and ensures protection against the destructive effects a polluted environment might cause as your artwork ages.

For Matting & Mounting Fine Art Prints    Acid and Lignin-Free Cotton Fiber    Protected Against Acidic Destruction    100% Cotton Fiber

100% cotton fiber pulp (99% alpha cellulose). It does not contain any post consumer waste recycled pulp. Paper is free of metal particles, waxes, plasticizers, and residual bleach peroxide. Sulfur content is less than 0.0008% reducible sulfur. Iron content does not exceed 150ppm and copper does not exceed 6ppm. No optical brightening agents are used in the pulp.

Alkaline sizing is used for both internal and external sizing. No alum is used in the manufacturing process.

Buffered with calcium carbonate 2 to 3% alkaline reserve; pH 9 ± 0.5; and acid-free.

Color dyes are light-fast and non-bleeding.

Pass the PAT (Photographic Activity Test) ISO 14523 (formerly ANSI IT9.16).

Lignin content is tested by TAPPI 236 cm-85 and has a Kappa number of less than 5.

The single ply sheets are laminated together using all natural starch adhesive.

Related Questions and Answers

Q: 1. Does this lens come with a lens hood?

A: Yes , hood is included

Q: 2. Is the sigma 100-400mm compatible with sigma teleconverters?

A: Hi, yes the Sigma teleconverters for Nikon, for instance, are compatible with the Sigma 100-400mm lens for Nikon.

Q: 3. I use a Canon 70D and currently have a Sigma 18-300mm....is it worth the money and why to buy a Sigma 100-400mm ?

A: This is a nice lens, light and sharp. I use it for a while. The quality of picture is good enough in day light. But it is not fast lens, it is not good in low light.

Q: 4. Will this fit a canon 90d?

A: Yes.

Q: 5. Is this compatible with Canon EOS 60D?

A: Yes, the Canon 60D is compatible with EF lenses like this Sigma.

Q: 6. Does this lens have a zoom lock to prevent lens creep while carrying it?

A: Yes, it has a zoom lock

Q: 7. Will this lens work on the Nikon D810?

A: I use this lens on my D810 all the time for wildlife photography. I find it easier to work with that the 150-600 when I'm moving around a lot. Very happy with the results from this lens.

Q: 8. Is the sigma 100-400 compatible with a Nikon D7000?

A: I had read recently that as long as the D7000 has the latest update, that it would be compatible. So I tried it with mine yesterday, and it seemed to function very well. The autofocus was very fast, and all of the exposure readings functioned as well. It was during the late afternoon/evening hours with overcast, so the lighting wasn't all that great, but it functioned as expected.

Q: 9. is that attache with canon 700d ???

A: Yes this will attach to a Canon 700D

Q: 10. Which lens is better overall (build quality, weather sealing, image quality, focus and value) the Sigma AF 150-600 F/5-6.3 DG OS HSM C or the Sigma 100 - 400mm F5-6.3 DG OS C?

A: Both lenses are under the Sigma Contemporary line. They have the same construction. Optical quality on the Sigma 150-600mm f/5-6.3 DG OS HSM Contemporary Lens slightly higher considering you have a longer zoom range.