There are actually 4 variantes. Now personally I'm inclined to say that "made of" is short for "made out of". Made from: We often use made from when we talk about how something is manufactured: Plastic is made from oil. Made of: We use made of when we talk about the basic material or qualities of something. It has a meaning similar to ‘composed of’: She wore a beautiful necklace made of silver. Made out of: We usually use made out of when we talk about something that has been changed or transformed from one thing into another: In the 1970s, it was popular to have candle-holders made out of wine bottles. Made with: We use made with most often to talk about the ingredients of food and drink: This dish is made with beef, red peppers and herbs. see http://dictionary.cambridge.org/fr/grammaire/grammaire-britannique/made-from-made-of-made-out-of-made-with

Sometimes they are used interchangeably, but there are differences. Sorry if my examples are bad because this one is tough to explain: Made of example: That paper airplane is made of paper. In that example, the entire airplane is purely paper. You can imagine some kid folded a piece of paper to look like an airplane. Made from example: That paper is made from trees. In that example, you're still holding paper. Except obviously you're not holding part of an actual tree. Paper is made, in part, from trees. In summary, "made of" kind of points out what the physical attributes are. (e.g. that cabinet is made of wood, that bag is made of plastic, etc). "Made from" only points out an origin of the object, but not necessary the object itself. (e.g that cabinet is made from trees, that bag is made from polymers and molecultes, etc) Let me know if that helps because it's hard to explain.

"Made of" is used when the material that consists the object you're talking about DOESN'T HAS its nature changed, for example: A chair is made of wood. And "made from" is used when the material that consists the object you're talking about HAS its nature changed, for example: The paper is made from wood.