Pencils Put in Garbage Cart Ways to Reduce Use Mechanical Pencils Instead Cut down on the waste caused by wooden pencils, which can’t be recycled, by switching to mechanical pencils. They can be reused indefinitely, but are usually not recyclable because they are made of plastic #6. Purchase Recycled Pencils Cut down on the number of trees that are used to make wooden pencils with a recycled pencil. TreeSmart, for example, makes their pencils out of recycled newspaper.