Copyright seals were applied somewhat haphazardly so are not reliable for dating. Also examine the quality of the impression and provenance for dating.
|A1||1909-1916.2 Round3, diameter 10mm approx. Watanabe ワタナベ in katakana.
1915-1924.4 Round, diameter 6mm5 approx.
|*||1921. Yoshida prints. The Watanabe family seal is followed by kanji reading publisher.|
|B||1924-1930. Reads copyright Watanabe Shozaburo. 版権所有渡邊庄三郎|
|**||1925-1928. Shunsen prints. Reads published by Watanabe. 渡邊工|
|C||1927-1932. Reads published by Watanabe. 版元渡邊版画店|
|D||1929-1942. Colloquially referred to as the 'sausage' seal. Reads copyright Watanabe Shozaburo. 版権所有渡邊庄三郎|
|E||1931-1941. Reads copyright and not to be reproduced without permission. Note the border-line breaks.|
|F||1932-1942. Reads published by Watanabe in Ginza.|
|G||1934-1941. Reads designed by Watanabe in Ginza.|
|H||1942-1945. Reads designed by Watanabe.|
|I||1945-present.6 Round, diameter 6mm to 7mm.7|
|J1||Before 1923. Label adhered to prints before the Kanto earthquake.|
|J2||After 1923. Label adhered to prints after the Kanto earthquake.|
|K||1928-1960. Commonly called the 'gift' seal.8 A less frequently seen substitute of the round seal. Watanabe わたなべ in hiragana.|
|L||1979. Copyright seal on commemorative edition prints. Reads copyright Watanabe Tadasu. 版元銀座渡邊規|
|M||1989-2019. Red colour. Heisei era seal. Indicates a print from older woodblocks, not necessarily original woodblocks. 9|
|N||2012-present. Indicates a reproduction, that is, a print made from newly carved woodblocks. Reads copyright Watanabe Shoichiro. 版権所有渡邊章一郞|
|O||2019-present. Black colour. Reiwa era seal. Indicates a print from older woodblocks, not necessarily original woodblocks. 9|
1 Following the nomenclature of the Hasui catalogue (Hotei), the first copyright seal is, logically, the A seal.
2 Date ranges described by Watanabe Tadasu and amended very slightly based on new data.
3 There was also a very rare square version of the seal.
4 Pre-Kanto-earthquake prints are generally easy to identify regardless of seals. They generally exhibit a greater number of impressions, less saturated colours, extensive use of visible baren lines, and printing on quite dry paper.
5 This seal continued on Shinsui prints until the 1960s. Shinsui prints were limited editions and rarely reissued.
6 Designs that were first issued in the late 1920s or 1930s with round seals are usually identified as post-war prints.
7 Watanabe Shoichiro and leading Hasui scholar Shimizu Hisao have each stated that the round hanko seal applied on any particular day, its size and colour, was essentially random. Prints verified from the 1940s-50s typically had 6.5mm to 6.7mm diameter although there were many outliers ranging from a fraction under 6mm (without the outer circle) to a fraction over 7mm. The mistaken belief of older prints having smaller seals has been attributed to Westerners misunderstanding how hanko seals were made and employed by Japanese.
8 Watanabe actually had a separate seal for gifts (shintei seal, 進呈).
9 Prints on which this seal appears have usually had many of their colour blocks recarved e.g. Hasui and sometimes all woodblocks recarved e.g. Toyonari. Watanabe describes these as atozuri, which means later prints (as opposed to shokizuri, early prints).
Note 1: Printer seals
|P1||1944-1951. Reads printer Ono Gintaro (1884-1965). Designated P1 in Hotei.|
|P2||1937-1944. Reads master printer Ono Gintaro. 摺師斧銀太郎|
Prints with Gintaro's seal may be dated. He was printer for Watanabe from 1917 to 1956 approx. Note that the P2 seal, master printer, actually pre-dates the P1 seal, which simply reads printer.
Note 2: Fake and forged seals
Unscrupulous dealers have been known to fake seals A, B and D. Their aim is to make a print appear older and therefore increase its perceived scarcity and market value.
It is recommeded to always examine the impression as the difference between an early impression and later impression is quite apparent. Early impressions tend to have clear and sharp lines. Later impressions from worn woodblocks can be quite blurred in appearance. A later impression with early seals is implausible.
It is recommended to be especially sceptical when two seals appear on a print. This may be legitimate, however, it is unusual and it's possible a fake seal was added to make the print appear older.
Later impressions missing all seals often sell for significant premiums at auction. These prints are typically unauthorized prints made by the printer and sold by the printer or his estate. A printer was in fact dismissed for selling unauthorized Hasui prints. Significant premiums at auction require at least two people - at least two people perhaps intending on applying fake seals for profit.
Note 3: Reproductions
Reproductions with seal N were very well carved and create high quality impressions. In many ways these are superior prints to those with seals M and O that may retain some link to original woodblocks. Those weathered and worn woodblocks, especially those first issued in the 1920s or 1930s, result in quite poor impressions.
updated July 2022