Any individual seriously interested in collectible knives and swords will tell you that counterfeit weapons can ruin an otherwise perfect collection.  Unfortunately, because mint, or even good condition collectible knives and swords have a high monetary value, many people will try to make replicas.  Today, even museum curators highly experienced with collectible knives and swords may have pieces in their collection that are counterfeits. Among other things, individuals intent on producing counterfeit collectible knives and swords have gotten remarkably good at it.  Because there are many specimens available in museums, these individuals have plenty of opportunity to study wear marks and other characteristics. It has also become much easier to replicate wear patterns and stylistic aspects with modern tools.  As an example, even a flint knife or other stone object can be produced and made to look like it is an  antique in just a matter of hours. In addition, you may also come across situations where collectible knives and swords have been smuggled out of legitimate historical sites and sold on the black market.  Typically these items are authentic, but are supposed to be up for sale.  Among other things, there is a very high probability that the nation where the collectible knives and swords were found would not approve of the items being sold.  While having a paper trail to accommodate the item of question may help, it is important to realize even these can be forged or duplicated. It is important to consider how you would feel if someone stole a family heirloom from your home and then turned around to sell it for a high price.   Chances are you would be extremely upset and want to take legal action against the thief.  Many countries feel exactly this way  when it comes to protecting their cultural heritage.  As a result, there are very stiff fines and other penalties associated with the sale, and even ownership of black market collectible knives and swords. Finally, you will want to give some thought to the condition of the collectible knives and swords that you are looking at.  As with any other type of collectible item, mint condition specimens are the ones most prized.  That said, if you have a good idea of the price range for specific items, you may decide that a less perfect item is still a good value.  You may even find that these objects add charm and uniqueness to an otherwise pristine collection. With a little bit of attention to detail and awareness, you should be able to build up a fairly decent set of collectible knives and swords.  Even though authentic historical items may be difficult to find, they are available on the legitimate markets.  That said, depending on your budget and experience with collectible knives and swords, you may find it best to start with contemporary items sold by the original manufacturer.  In many cases, these weapons will give you a firm foundation for your collection as well as help you learn how to assess antique items later on.