Do you seal your manga or anything else special?

As the title indicates, I'm wondering if anyone seals their manga or does anything special to take care of them? I've been thinking of getting this: http://www.amazon.com/dp/B002MVQ7W0/ref=wl_it_dp_o_pC_nS_ttl?_encoding=UTF8&colid=3Q80TQQVS3PVG&coliid=I15Y7S6MNJZ98R to seal my manga but not sure how useful that would be. Also wondering how easy it is to seal/reseal, as well as sizing since modern comics are bigger than manga.

For those that do use seal bags, what large bags do people use for art books and anime production/animation notes that are quite larger compared to manga?