The Inart A5 Sewn Sketchbook with 40 Sheets (1550399055) has a sewn binding, which is more resistant and durable than the simple gluing or spiral binding of the other versions in the line, making it the most robust option for intensive use over time. The 40 sheets of 165g paper, an intermediate weight between the 110g and 180g versions in the collection, balance capacity for more demanding dry techniques with a relatively lightweight and easy-to-carry pad. Because it is sewn, the sketchbook opens almost completely without the sheets coming loose over time, even with frequent use and daily transport. It is ideal for those looking for the most durable sketchbook in the Inart line, suitable for students and artists who regularly take the sketchbook out of the studio and value a binding that withstands daily wear and tear.