Vermeer produced transparent colours by applying paint onto the canvas in granular layers, a technique called pointillé. No drawings have been securely attributed to Vermeer, and his paintings give few clues to preparatory methods.
Some historians has speculated that Vermeer used a camera obscura to achieve precise positioning in his compositions, and this view seems to be supported by certain light and perspective effects which would result from the use of such lenses and not the naked eye alone.
There is no other seventeenth century artist who from very early on in his career employed the incredibly expensive pigment lapis lazuli, natural ultramarine. Not only used in elements that are intended to be shown as appearance: the earth colours umber and ochre should be understood as warm light from the strongly-lit interior, reflecting its multiple colours back onto the wall.
This working method most probably was inspired by Vermeer’s understanding of Leonardo’s observations that the surface of every object shares the colour of the object next to them. This means that no object is ever seen entirely in its natural colour.
Even after Vermeer’s supposed financial breakdown following the so-called rampjaar (year of disaster) in 1672, he continued to employ natural ultramarine most generously, such as in the previously mentioned “Lady Seated at a Virginal.” This could suggest that Vermeer was supplied with materials by a collector.