For Giorgio Vasari, a sixteenth-century artist, architect and pioneer of the artist biography, drawing was 'the father of our three arts: architecture, sculpture, and painting.' Vasari, who also wrote extensively on technique, was here discussing the concept of disegno. Often this is translated simply as 'drawing', though the term had more complex connotations in the Renaissance than our understanding of it. Not simply referencing the manual act of drawing, it also conveyed the artist's capacity to invent or create a design.

It is no surprise, therefore, that learning the art of drawing – and continuing to develop this skill throughout a career – was fundamental to the Renaissance artist's trade, as current exhibitions in London (at the Royal Academy and The King's Gallery) and Edinburgh (at the Royal Scottish Academy) attest. During the fifteenth and later centuries, drawing began to evolve into an art form in its own right.

Drawing's foundational role for all other arts is encapsulated by this c.1573 engraving by Cornelis Cort from, fittingly, a drawing by Jan van der Straet, the prodigious Bruges-born artist active mainly in Florence. This allegorical work shows a busy, imagined, workshop bristling with artists from different fields, each identified by a label. At the centre, a sculptor puts the finishing touches on a statue of Roma (the deified personification of Rome) – this is statuaria, the carving of hard materials. Also depicted are sculpting, painting, metal casting, engraving and architecture. Spread across the lower half of the image are the apprentices, all engaged in one activity – drawing.

Already at the turn of the fifteenth century, Cennino Cennini, in his treatise The Book of Art, emphasised the importance of mastering draughtsmanship for the prospective painter: 'the foundation of art and the beginning of all these manual skills lies in drawing and the application of colour.' Cennini's manual on late medieval and early Renaissance painting provides a fascinating snapshot of the training, practice and life of a working painter.

Cennini's text stressed the importance of becoming proficient in drawing before moving on to the other aspects of art, such as painting or working with other materials. He advised young artists to spend years practising and perfecting their drawing skills.

During the Middle Ages and Renaissance, artistic apprenticeships were highly regulated formal agreements, often lasting several years. Parents paid fees or provided services in exchange for a child receiving training in what they hoped would be a lucrative trade. Apprentices lived with the master and gained experience in different tasks and techniques, such as grinding pigments, preparing sculptural materials and tools, preparing canvases and, of course, drawing. Gradually, apprentices gained artistic responsibilities and took on independent work, either within the workshop or as their own master.

Studying and copying anatomy was one way for budding artists to learn how to depict realistic proportions, dynamic poses and lifelike forms in their artworks. This striking sixteenth-century study of a pair of écorchés (anatomy studies showing musculature as if the body were flayed) is a companion piece to another pair. Each was created by the same artist, perhaps from the circle of Bolognese artist Bartolomeo Passarotti. The figures' stance, particularly the bent legs and awkwardly held necks, suggests that they were copied from suspended corpses – a practice also seen in Cort's engraving.

Interestingly, the figures in the écorchés are not unique. They recur, with slight variations, in other drawings by different artists now found in collections spread across Europe. This suggests they derive from a now-lost set of originals that once circulated widely as learning tools. This may have been a model book (later sketchbook), the term used since the Middle Ages for collections of drawings used as references or for training.

Bones of the Human Hand and Wrist, and of the Elbow Joint (recto); Head of a Man (verso)

This sixteenth-century study in chalk, pen and ink attributed to the school of Michelangelo shows the skeletal structure of a human hand and wrist, and, separately, an elbow. Realism was preferred over perfection. There are abnormalities to the bone of the hand – including an extra bone – as well as signs of arthritis.

Although the exact link between this drawing and Michelangelo is unknown, that great Renaissance artist was fascinated by anatomy, particularly muscles and bones. He reportedly attended or participated in the dissection of corpses, sketching what he saw, and working from live and sculptural models. This informed Michelangelo's sculptures and paintings, with their dynamic poses and compositions. His paintings are full of weighty forms, especially in contexts for which this would have previously been unexpected. The Virgin Mary in the artist's Doni Tondo (1505–1506) is far from sylph-like, instead displaying enviably toned bicep and forearms.

16th C, pen, chalk & brown ink on paper by school of Michelangelo (1475–1564)

Like many others, the sheet of paper bearing the anatomical sketch was not just used on one side. Rather than anatomy, the sheet's reverse (or verso) shows a study in red chalk of a man's head in profile. Paper was an expensive commodity in the Renaissance, so artists used as much of each sheet as was feasible. In a workshop setting, it was not unusual for several artists to work on the same sheet of paper at different times. This may have been the case here.

This delicate study, on green prepared laid paper, of a seated woman, her drapery pooled around her, is attributed to the workshop of Netherlandish painter Hugo van der Goes. Faint marks on the drawing's surface indicate that it is a tracing of an earlier, original drawing. It is impossible to say if this particular drawing was copied during a period of workshop training. Rather, it may well have been used to produce multiples. The subject, tentatively identified as Saint Catherine of Siena, but sometimes as Saint Barbara, appears in more than 20 panel paintings and 13 miniatures from the 1480s to the sixteenth century. This practice of repeating or reproducing motifs on different paintings, sometimes with subtle adjustments, was widespread.

As well as individual elements, full-scale preparatory drawings, known as cartoons, were transferred and used to design paintings, frescoes, or tapestries, such as this 2.5 metre by 1.3 metre preparatory drawing for a wall painting for Whitehall Palace. Completed by Hans Holbein the younger in 1537, it was commissioned by Henry VIII, who is depicted in this section.

Artists, like Holbein here, worked out a composition's intricate details on paper before transferring the sketch onto the final surface. This ensured accuracy in composition and proportion. This practice also allowed different elements to be undertaken by various workshop members – not only the master and apprentice but also other affiliated artists.

Another of Holbein's drawings, this design for a glass painting, may have had a different purpose. Detailed drawings such as this could be used during the commissioning process to show patrons, or potential patrons, what a finished artwork might look like. This design, dating to perhaps 1520, when Holbein was still active in Basel, contains a blank shield. A patron's coat of arms would be added to this space. The lack of the coat-of-arms might suggest that the drawing was simply unfinished. Alternatively, it might indicate that this was a speculative drawing, used to advertise Holbein's skills to prospective ecclesiastical patrons (a mitre and crozier, symbols of bishops or abbots, are prominently featured).

Detail from 'Saint Paul and Saint Barnabas at Lystra'

Cartoons or other preparatory sketches, especially by exceptionally skilled artists, could inspire their own right. This whimsical sketch, of uncertain date, is a copy of two young boys from the foreground of Raphael's cartoon for The Sacrifice at Lystra, one of the tapestries destined for the Sistine Chapel. Raphael's work has inspired this unknown artist to create their drawing, subtly adapting the original.

Painters and sculptors also used drawings to work out their designs, sketching out different alternatives to perfect an element or the whole composition, or to think through elements with no particular commission in mind. This was a key part of the creative side of disegno. This vivid, rapid-fire sketch by Florentine artist Fra Bartolomeo is on the verso of a preparatory drawing for an altarpiece. The two figures in the lower left have yet to be linked to any surviving paintings by the artist. However, their spontaneous lines suggest an artist working through the design process. Not all drawings were preparatory.

This beautiful, small sketch attributed to Fra Angelico, dated around 1432, has key elements – Jesus's wounds and halo – picked out in red wash and lead white. Although related to the artist's Deposition for the Strozzi Chapel in Florence's Santa Trinita (now in the Museo di San Marco), it is believed, based on its size and unusual, Christocentric subject matter, that this was made as an object of private contemplation – a final artwork in its own right.

Whether the foundation on which other artworks were built, or treasured as its own art form, drawing was never far from Renaissance artistic practice.

Louisa McKenzie, writer

This content was funded by the Bridget Riley Art Foundation