These dealer-led initiatives, now firm fixtures in the calendar, follow the same, simple format of a series of simultaneous exhibitions over the same week around Mayfair and St James's - essentially a marketing exercise to encourage visitors, old and new, and kill off the idea of the aloof gallery stereotype.
Obviously, participating dealers are keen to sell, but the idea is that this is an educational as well as commercial event and many dealers are more than willing to impart their knowledge to new visitors - as the old saying goes, today's lookers are tomorrow's buyers.
Master Drawings London, the brainchild of Yorkshire-based art dealer Crispian Riley Smith, runs this year from June 27 to July 5, and Master Paintings Week, started by the Old Master dealers Johnny Van Haeften, Konrad Bernheimer and Richard Green, is from June 29 to July 6 - both coinciding with Masterpiece London down at the Royal Hospital Chelsea (June 27 to July 4). Although independently organised and different in age - MDL is in its 12th year and MPW its fourth - they make a mutually beneficial duo and both capitalise on the surge of international curators, collectors and dealers that the major Old Master sales in early July bring to London.
See the respective websites for a full list of participants and events, but here is a roundup of what MDL and MPW will be serving up this year.
Master Paintings Week
For the fourth year in a row, Master Paintings Week returns from June 29 to July 6, a collaboration between 23 galleries and three auctioneers - Christie's, Sotheby's and Bonhams - who all hold major Old Master sales during the week.
The series of concurrent exhibitions and lectures takes place across St James's and Mayfair and joining the fray for the first time this year are Haldane Fine Art, Noortman Master Paintings and Theo Johns Fine Art. Although at heart this is a salute to Old Masters, there are no date constraints and the paintings on show date from the 15th century to the contemporary.
As with last year's MPW, a number of participants will divide their stock and also exhibit at Masterpiece London at the Royal Hospital Chelsea from June 27 to July 4. They include Colnaghi, Stair Sainty, Sphinx Fine Art and Philip Mould.
This year, the organisers have decided to forego a printed catalogue in favour of an online catalogue and a free iPhone app, featuring a map of galleries, auction houses, hotels and restaurants, to help visitors get around and find somewhere to rest their weary feet. There will also be ten black cabs and five rickshaws, sporting the MPW logo, on hand to ferry gallery-goers about.
As usual, while the majority of participants hold general shows, others home in on specific themes and below is one example. For a full catalogue see www.masterpaintingsweek.co.uk
In the field of Old Masters, provenance is key. Noortman Master Paintings take part in Master Paintings Week for the first time this year at 13 Old Bond Street and their star piece is Portrait of a Gentleman by the Venetian artist Bonifazio de'Pitati, called Bonifazio Veronese (1481-1553).
The 2ft 2½in x 2ft 8½in (98 x 83cm) oil on canvas was painted in the 1520s and was formerly in the Leuchtenberg collection after being acquired by Eugène de Beauharnais (1781-1824), 1st Duke of Leuchtenberg, son of Joséphine Bonaparte and adopted son of Napoléon Bonaparte. It then passed to his son Maximilian, 3rd Duke, who married Grand Duchess Maria Nikolaevna of Russia, daughter of Emperor Nicholas I of Russia. Later it was in Florence's Contini Bonasconi collection before being bought by the collector and philanthropist Samuel S. Kress in 1929 and it was then passed down through his heirs until 2001.
Noortman will ask $1.25m for the painting, which is one of a small group of characteristically Venetian portraits by Bonifazio Veronese and shows an unknown man who, judging by the fur-lined grey cloak, black stole and black beret, was an important figure in Venetian society.
Other themed exhibitions at MPW participants:
Masters: Young and Old at Piacenti Art Gallery. Old Master dealers Emanuele and Leonardo Piacenti from Florence will use MPW 2012 to officially launch their new permanent London gallery at 10 Bury Street, joining forces with New York dealer Jason Jacques. The Piacenti's Italian paintings by 15th to 19th century artists such as Benedetto Gennari, Guiseppe Bezzuoli and Jacopo Amigone will be shown alongside the American abstract painter Martin Kline, with the aim of introducing collectors of both contemporary art and Old Masters to a new genre.
Waters Run Deep: An Eternal Ribbon of Life at Deborah Gage (Works of Art).
The depiction of water, whether employed as a classical motif or in the seascapes of the Dutch Golden Age, is the central theme of Deborah Gage's show at 38 Old Bond Street.
A Long Neglected Master: Nicolaes Van Haeften at Johnny Van Haeften Gallery.
Johnny Van Haeften started collecting his namesake's work after he inherited a group portrait by the artist, The Van Haeften Family Making Merry, in 1975. During MPW he will hold a loan exhibition of this obscure 17th century genre painter, a mix of paintings and prints from his own collection and those from another private collector.
Foppa, Zenale and Luini: Lombard painters before and after Leonardo at Robilant + Voena, June 20 to August 17.
The painters of Lombardy in the 15th and 16th century, before and after the influence of Leonardo da Vinci, take centre stage in this exhibition which will include part of the corporate collection of Swiss bank PKB Privatbank, Lugano.
The Point of No Return at Haldane Fine Art, June 25 to July 7.
An exhibition of paintings depicting pivotal moments from the bible and classical mythology, such as The Exodus of the Twelve Tribes of Israel, The Flight into Egypt and Adam and Eve in the Garden of Eden.
Frans Hals and the Haarlem School at Sphinx Fine Art, June 29 to July 6.
This show examines the influence of Haarlem painters in the Dutch Golden Age, based around the gallery's star piece, Frans Hals' A Tronie of a Young Man in the Costume of an Actor.
Master Drawings London
Once again extolling the subtle charm of works on paper, this year Master Drawings London takes place over the earlier dates of June 27 to July 5 to coincide with both the 20th century sales at the end of June and the Old Master auctions of early July.
Although nominally all about Old Master drawings, there is in fact a great breadth of watercolours, oil studies and drawings from 15th century works through the English watercolourists of the 18th and 19th century to 20th century pieces, as well as those by contemporary artists who continue to explore this most traditional and basic of mediums, the humble pencil and paper.
MDL is a little smaller this year than last, with 17 dealers from London, New York, Düsseldof, Zurich, and Madrid mounting exhibitions around St James's and Mayfair.
One dealer joining this year for the first time is Auguste Laube from Zurich, exhibiting at Daniel Crouch Rare Books on Bury Street.
For those with a more academic interest, for the first time this year MDL will host a lecture.
At 10am on June 28, at the Society of Antiquaries of London in Burlington House on Piccadilly, the forensic paper historian and paper analyst Peter Bower will give a talk titled First of all respect your paper: 500 years of artists and their papers.
Once again there will be a series of evening receptions at galleries during the course of the week, details of which can be found at www.masterdrawingsinlondon.co.uk
To Dickinson at 58 Jermyn Street for a scholarly watercolour show of the old school, albeit featuring an Italian, not an English artist as you might expect.
From June 18 to July 13, Simon Dickinson in association with Bill Thomson, will host an exhibition of watercolours by Italian Grand Tour artist Carlo Labruzzi (1748-1817), curated by Sir Timothy Clifford, former director of the National Gallery of Scotland.
According to the gallery, this is the largest group of Labruzzi's works to come on the market since 1960, a gathering of over 40 topographical drawings and watercolours of Rome, the Roman Campagna, Naples, the Marche and Venice.
The en plein air works are taken from two albums compiled by the artist and acquired from his widow in 1818 by Lord Wharncliffe. They were passed down by descent to the 7th Earl Fitzwilliam and eventually sold from Wentworth Woodhouse, Yorkshire, in 1948.
"We tend not to think of Italian artists as masters of watercolour," says Sir Timothy, "yet Carlo Labruzzi, landscape painter to the grandest of grand tourists, was greatly admired in his own day."
The work pictured, in pen and watercolour over traces of pencil, shows The Colosseum from the Palatine Hill. It measures 14¾ x 21¼in (38 x 54cm) and is priced at £50,000.
Day & Faber
It's not just secondary market works at MDL - in the age of installations and video art, the modest pencil and paper is still honoured by some contemporary artists too.
David Winthrop (b.1948), formerly rock band Supertramp's saxophonist, is a keen draughtsman and Day & Faber will hold the first large exhibition of his drawings and notebooks at 14 Old Bond Street from June 27 to July 5.
Throughout his career, Winthrop has drawn obsessively, keeping notebooks which he crams with all manner of weird and wonderful creatures, characters, landscapes and machinery, densely drawn with an architect's pen.
The works in the exhibition range in price from £500 to £2500.