Haphazardly pieced together over the decades, in accordance with the varying tastes and styles of different eras and individuals, the resulting collection spans a far wider range than most.

According to organizers, it offers a genuine cross-section of work by a variety of artists from across Italy, ranging from the end of the 1300s through to the start of the 1500s.

The major Italian schools of the century - Padua, Verona, Lombardy, Bologna, Venice and Florence - will all be represented, with finished works, workshop sketches, preparatory studies and life-drawings.

The exhibition was inspired by fresh research into the collection over recent years, which has resulted in a number of new attributions.

Among the most exciting finds for Renaissance experts are a Botticelli sketch of a child's head, and a Pipe-Player, by Costa.

The exhibit will also highlight recent discoveries on the wide variety materials used. Artists regularly used alloys of silver, lead, copper and even gold to carry out their work, as well as pens with ink from diverse sources, such as ashes, oak-gall and smoke residue.

In addition, the show features an unusual number of works using a "primed paper" technique that fell out of practice at the start of the 16th century.

This entailed applying a layer of coloured tempera to the paper as a base coat in order to make white lead brush strokes on top appear more luminous .

The base coat could be in a variety of colours, and a number of red, blue and green-hued works are on show. While the technique was fairly common, the base layer is highly vulnerable to light degradation, so the exhibit offers a rare opportunity to enjoy the effect.

Many of the discoveries spotlighted in the show, including the materials used and the seven works created with metal alloys, are being added to the International Database of Watermarks and Paper of Prints and Drawings.

The database was set up by the Dutch Institute for Art History in Florence in 2001, in a bid to record, digitalize, and study the structure of paper used for prints and drawings as well as artists' letters.

Botticelli, Verrocchio e oltre. Disegni italiani del Quattrocento dalle collezioni reali di Dresda (Botticelli, Verrocchio and Beyond. Italian Drawings of the 15th Century from the Royal Collections of Dresden) will run in the Dutch Institute from September 15 until November 5.