From what are egg cartons made?

From newspapers.

That curious shape –of angles, protrusions and subtle porosity- is strangely linked to one of the most traditional customs of modern societies: the publication of news on paper. The thousands of tons of newspaper that are thrown away daily, once collected and recycled, draw their last breath of useful life as the mainstay of one of the most common food items of Latin American families.

But there is more, much more.

Almost on a life or death mission, the boxes made from recycled materials or of fibers obtained from certifiably renewable plantations, safeguard the wines that travel thousands and thousands of kilometers by sea or air to end up as an accompaniment to fine dining.

Packaging for medicines follows a similar process. It emerges from large sheets of fine cardboard, which are then shaped in such a way as to protect the medicines that help alleviate some of our aches and pains.
Salmon, grapes, apples, cereals, pasta and even the latest electronic device we acquire are all protected by packaging made of fine cardboard, paper and carton: once we use and discard it, this is likely to pass through our hands again in the form of the carrier bag that we use to store the goods we buy at the mall, supermarket or neighborhood store.