A nice method to identify fakes, especially rebacks is their weight. A real Magic card from the early days usually has 1.72 to 1.74g. Later cards with holofoil stamp etc. might be a different (up to 1.78g).  There is quite some variance in the weight of cards and people spent a lof of effort to map weights of certain cards, but it is mostly in the second number after the comma. If a card is too much of it definitly should ring a bell. Everything 1.9g and up needs to be cloely investigated.

Some of the common fakes from china currently circulating have a weight of 1.92g to 1.94g.