Graves, who died in 2015 at the age of 80, originally designed Scallop in 2013, but its complicated dial engraving of curving symmetrical lines, which echo the scalloped edges of the face, proved challenging to produce.
The engraving is created to echo the effect of a technique called guilloché, which is generally reserved for fine jewellery.
"The guilloché engraving technique has been found in fine jewellery and on Faberge eggs since the 17th century," said Projects. "With its symmetrical rigour and shell-like geometry – a form favoured in many artefacts designed by Michael Graves – the Scallop watch is sure to become a highly sought after design icon."
Guilloché traditionally involved interlocking or interwoven patterns engraved into fine metal using a turning machine, known as a rose engine, which requires specific training to use.
For Scallop, the concentric pattern is made by overlaying the metal with a fine film and then using acid to dissolve the voids in the pattern, which are then removed. This creates an etching that is just 0.1 millimetres deep.
"The Scallop watch has taken more than three years to come to market, due to technical challenges that had to be overcome in order to achieve its original design intent," said Projects.
"After this etching treatment, the dial has a raised 'guilloché pattern' with plain recessed areas below it."
The dial is coloured using an ionic-plating technique, and is housed in a 40-millimetre-diameter steel case.
Each version comes with a strap that compliments the colourful dial. Celadon – a pale green colour favoured by Graves in many of his product designs and seen on his most famous piece of architecture, the Portland Building – is used for one of the dials.
Another version has a lavender dial with a blue strap, while a version with a rose gold-coloured case and face features a brown strap.
All three are available from today at Dezeen Watch Store.
Graves was one of the leading exponents of Postmodernism, a late 20th-century movement in architecture and design that championed decoration and bright colours.
He believed in democratic design for everyday use, and created a number of watches and clocks throughout his life for well-known brands like Projects, Alessi – for whom he also created the iconic 9093 kettle – and Pierre Junod.
His designs for Projects include the Grand Tour Dual Time, which is based on the architect's travel across Europe in his youth and keeps track of two different time zones.
His Newark Museum watch, named after the museum of the same name, for which he was masterplanner, was relaunched by Projects last year.