Which of the following items would not be classified as a non-machinable parcel?

Printed matter is classified as non-machinable due to its nature and specific guidelines established by postal services. It consists of items like books, magazines, catalogs, and other forms of written communication that are prepared specifically for mailing. In this case, the printed matter weighing 3 pounds would be designed according to postal regulations that accommodate such items, which are typically processed differently than parcels containing tangible goods.

In contrast, the other items listed - clothes, food items, and electronics - could potentially be classified as machinable parcels based on their weight, dimensions, and packaging, provided they meet the specific criteria for handling and processing. Therefore, printed matter is the correct choice for not being considered a non-machinable parcel in this context.