I think you are asking how to keep your pack dry. That is, keeping your pack from absorbing water. Don't know what fabric your pack is made from but spraying or washing just the pack with Granger's Waterproofer would be the way I would go. It's a versatile product which can be used on many different types of fabrics. It works well. Might have to ocassionally reapply it though. Then use the internal liner idea with or without the added safety of WP stuff bags to keep specific gear like your sleeping bag dry. Could also go with the a WP pack cover after waterproofing with the Grangers for added protection. Find the combination that works for you under your typical hiking situations. Hope that answers your question.