I was a picture framer for many years, working to a very high standard. Properly framed, an item should not be damaged at all, there are a variety of techniques that can be used for different media and could help greatly with conservation. Unfortunately the majority of framers I have encountered have not had more than the most basic training and use poor materials and techniques. The process is skilled, time consuming and inevitably expensive if done to a high standard, but well worth the effort if you want something to look it's best.
John.