both sides of the sheet of paper means that it will remain a sketchbook... which is the idea of the sketchbook, most are pretty decent paperworks. They remain inside the sketchbook. There's a loss/win (purist) feeling to a completed sketchbook. Sketchbooks reveal a lot of the inner persona of the artists. I did two pages today, and said to myself " let's look at some sketchbooks". I remember seeing a Paul Gauguin sketchbook at the Grand Palais retrospective in 2018 or there about...pre Covid... it was very contemporary, he used collages before Picasso ! his pencil drawings were "mind boggling" so swift and precise... Sketchbooks the hidden treasures.