The Massey Harris poster was actually reprinted at some point in its life. The poster that is in the archives is not the original, therefore it is difficult to say what condition it may have been in prior to the reprinting. The reprinting was likely done in an effort to preserve the poster. It is hard to pinpoint when it occurred, there is no date, but the printing company was founded in 1987 and appears to now be out of business. The reprinting was likely done in an effort to preserve the paper and ensure that the ink on the poster did not fade.
Now that the poster has been printed using a water based ink, using a technique called laser printing (shown above), it is much less likely to fade. Even still it is kept in a cool dark place in the archives to ensure that the paper does not disintegrate and the ink does not fade.