Giuponi's Sesto for building a  gondolin.

The principal system used in boat design in the Venetian boatyards is the sesto, a full-scale template that, by rotating and moving guided by the marks on its surface, allow for the direct creation of all the frames.

Although technical drawings showing the classic longitudinal, transverse and plan views exist, they are used only for bureaucratic purposes.

The advantages of this template system are evident: full-scale drawings are made directly without having to enlarge them at the lofting stage; the sesto can be positioned on the block of rough wood for a more rational use of the material; one or more parameters of the boat can be changed by varying the scale of the marks; families of similar curves can be generated while avoiding possible irregularities in the form of the hull, etc.

This system, albeit with many variations, is so rational and practical that it is still used in most of the traditional boatyards around the world.

The only disadvantages are the lack of visualization of the completed boat and the impossibility of calculating volumes, stability, etc. However, neither of these were required by the boatbuilders who knew the appearance and characteristics that the finished boat would have.

Nomenclature of the marks.

Sagome at the Bovo boatyard, Burano.

Sagome and sesti saved from destruction.