'Made of' vs. 'Made from'

Solution 1:

I've heard a radio program on this topic.

Made of is used when the material the subject consists of doesn't change during the process of making the subject. As in the example by Armen elsewhere on this page:

Chairs are made of wood.

Here, wood is still wood. It doesn't transform into something else.

On the other hand, made from is used when the material changed its nature. Again, another Armen example:

Paper is made from wood.

Now, wood disappeared — it was transformed into paper.

Some more examples:

• The house is made of bricks. [They are still bricks.]
• Wine is made from grapes. [Grapes turn into wine.]

Solution 2:

‘Made from’ is often used to describe manufacturing processes . . . ‘Made of’ emphasises the inherent material or qualities of something, and has a meaning similar to ‘composed of’.

‘Cambridge Grammar of English’ by Ronald Carter and Michael McCarthy