The present invention relates to a drawing assisting tool, comprising at least one thin template with a set of solid and dashed grooved lines, in which said grooved lines are adapted to guide the drawing of at least one complete spatial body on a flat surface.

The present invention relates to a drawing assisting tool, comprising at least one thin template with a set of solid and dashed grooved lines, in which said grooved lines are adapted to guide the drawing of at least one complete spatial body on a flat surface.

Disclosed is a powder build material handling system for a three-dimensional printer. The system comprises a delivery system. The delivery system is to carry powder build material in a flow of gas from a powder build material supply. The delivery system is to filter the flow of gas to separate the powder build material from the flow of gas. The delivery system is to direct the filtered flow of gas to the powder build material supply to form a closed system.

Disclosed is a powder build material handling system for a three-dimensional printer. The system comprises a delivery system. The delivery system is to carry powder build material in a flow of gas from a powder build material supply. The delivery system is to filter the flow of gas to separate the powder build material from the flow of gas. The delivery system is to direct the filtered flow of gas to the powder build material supply to form a closed system.