How To Tell Synthetic Fiber Wigs And Human Remy Wigs?

For us who often wear lace wigs, the quality is very important.As is, most synthetic fiber wigs do heavy harm to sensitive skin,while human remy wigs are safe.But how to tell the differences between them.recently,I find 2 simple methods on http://www.rpgshow.com to distinguish.
1. You can cut a single short hair and burn it. Human hair smells the same as your own hair when burning because it has protein inside. While synthetic fiber doesn't smell the same way.
2. You can take the wig to any professional in salon, he will tell you it's human hair without doubt.
BTW, hair extensions are in the same situation.
Do you have other creative but simple , easy methods to differentiate the 2 items??