strategies that include the implementation of alternative climate control systems to replace or supplement traditional high-energy consuming HVAC systems as well as the introduction of passive preservation techniques. Rather than maintaining a flat line, consistent 24/7 condition for a collection's environment, fluctuation can occur within acceptable limits to create a preservation environment while also thinking of energy efficiency and taking advantage of the outside environment. Bound materials are sensitive to rapid temperature or humidity cycling due to differential expansion of the binding and pages, which may cause the binding to crack and/or the pages to warp. Changes in temperature and humidity should be done slowly so as to minimize the difference in expansion rates. However, an accelerated aging study on the effects of fluctuating temperature and humidity on paper color and strength showed no evidence that cycling of one temperature to another or one RH to another caused a different mechanism of decay. The preferred method for storing manuscripts, archival records, and other paper documents is to place them in acid-free paper folders which are then placed in acid-free of low-lignin boxes for further protection. Similarly, books that are fragile, valuable, oddly shaped, or in need of protection can be stored in archival boxes and enclosures. Additionally, housing books can protect them from many of the contributing factors to book damage: pests, light, temperature changes, and water. Contamination can occur at the time of manufacture, especially with electronic materials. It must be stopped before it spreads, but it is usually irreversible. Preservation criteria Making a proper decision is an important factor before starting preservation practices. Decision making for preservation should be made considering significance and value of materials. Significance is considered to have two major components: importance and quality. "Importance" relates to the collection's role as a record, and "quality" covers comprehensiveness, depth, uniqueness, authenticity and reputation of the collection. Moreover, analyzing the significance of materials can be used to uncover more about their meaning. Assessment of significance can also aid in documenting the provenance and context to argue the case for grant funding for the object and collection. Forms of significance can be historically, culturally, socially, or spiritually significant. In the preservation context, libraries and archives make decisions in different ways. In libraries, decision-making likely targets existing holding materials, whereas in archives, decisions for preservation are often made when they acquire materials. Therefore, different criteria might be needed on