How to date Watanabe publisher seals

Watanabe Shozaburo publisher seals on prints by Kawase Hasui, Ito Shinsui, Natori Shunsen, Ohara Koson among other shin-hanga artists. The following was based on nomenclature introduced by Watanabe Tadasu (Nihon Keizai Shimbun, 1982), and updated based on new data such as data from registering many thousands of prints and seals in a database, longitudinal data from block wear, and reliable provenance of selected prints.

1	March 1909–1916. Round, diameter 10mm approx. Watanabe ワタナベ in katakana. 1915–1989. Round, diameter 6mm to 7mm.¹ 1989–present. Round, diameter 7mm.²
A1	1926–1930. Type 1 seal was most likely earlier, 1926–1928. Reads copyright Watanabe Shozaburo (aka Kako). 版権所有渡邊庄三郎
A2	1926–1930. Type 2 seal was most likely later, 1928–1930.
B	1930–March 1932. Reads published by Watanabe. 版元渡邊版画店
C1	January 1931–March 1933. Commonly referred to as the Sausage seal. Type 1 seal not seen after 1933. Reads copyright Watanabe Shozaburo. 版権所有渡邊庄三郎
C2	July 1932–1942.
D	December 1933–1942. Watanabe mon (family seal) is followed by kanji reading copyright and not to be reproduced without permission.
E	1940–1941. Reads published by Watanabe in Ginza.
F	1940–1943. Reads designed by Watanabe in Ginza.
G	1941–1944. Reads designed by Watanabe.
H	c.1979. Reads copyright Watanabe Tadasu.³ 版元銀座渡辺規
I	1989–2019. Red colour. Heisei era seal. Indicates a print from older woodblocks, not necessarily original woodblocks.⁴ Watanabe わたなべ in hiragana.
J	2012–present. Indicates a reproduction, that is, a print made from newly carved woodblocks. Reads copyright Watanabe Shoichiro. 版権所有渡辺章一郞
K1	2019–2024. Black colour. Reiwa era seal without publisher seal. Indicates a print from older woodblocks, not necessarily original woodblocks.⁴
K2	January 2025–present. Black colour. Reiwa era seal with publisher seal. Indicates a print from older woodblocks, not necessarily original woodblocks.⁴

¹ During this interval, it is not possible to date a print based on which diameter of round seal was applied. A round 7mm seal was first seen on Fritz Capelari prints in 1915. The round seal continued on most prints until late 1926. For example, early impressions of Hasui's Zojoji Temple in Shiba (1925) featured the round seal. This seal was applied to Hasui's small prints, commissions, and intermittently to his oversize prints in the late-1920s, 1930s and early 1940s. This seal was applied to Shinsui prints continuously from 1917 to the 1960s. It was applied more frequently from the late 1930s and became the primary seal again from 1947. Note that many prints actually printed in the late 1930s and early 1940s were sealed after the war with the round seal - seals were applied later when prints were removed from inventory. A round 6mm seal was applied to many prints designed in the 1960s and 1970s.

The publisher Watanabe Shoichiro and leading scholar Shimizu Hisao each have stated that the round hanko seal applied at any particular time - its size and colour - was essentially random. Prints verified from the 1920s to 1940s usually had 6.5mm diameter seals (measured by 1200dpi scanner) although there were outliers ranging from 5.5mm (without the outer circle) to 7.1mm. These seals were carved by hand by a specialist hanko-maker and, when they wore out, another seal would be ordered and a 1mm difference was not anywhere in anyone's mind to pay attention to.

The mistaken belief directly correlating earlier impressions and smaller seals has been attributed to an American, Irwin J. Pachter, misunderstanding how hanko seals were made and applied by Japanese.

² The round seal was standardised to 7mm at the beginning of the Heisei era. The round seal typically measures 7.3mm to 7.5mm on prints with Heisei and Reiwa seals - variance due to water in the paper (washi expands with humidity) and pressure applying seal.

³ Various artists and limited edition prints. On Hasui commemorative edition prints, commissioned by Mainichi Shimbun, it was accompanied with round 7mm seal.

⁴ Prints on which this seal appeared have usually had many, if not most, of their colour blocks recarved. A few prints such as by Toyonari and small Hasui prints were reproductions with new keyblocks and colour blocks. Watanabe described these as atozuri, which translates to later prints (as opposed to shokizuri, early prints).

Note 1: Printer seals


P1	P2	P3	P4

P1	1938–1944. Reads master printer Ono Gintaro. 摺師斧銀太郎
P2	1943–1951. Reads printer Ono Gintaro (1884-1965).
P3	c.1997. Reads printer Horikawa Shozaburo (1938-).
P4	September 2025.

Gintaro was printer for Watanabe from 1911 to 1956 approx.

Note 2: Miscellaneous seals

M10

M11

M12

M13

M1	1916–c.1923. Square Watanabe personal seal. Watanabe わたなべ in stylised hiragana.
M2	c.1916–c.1917. Square Watanabe publisher seal. Watanabe ワタナベ in katakana.
M3	c.1923–1960, 1974, 1979. Watanabe's personal seal. Erroneously referred to as the Gift seal (see M7).
M4	1921. Hiroshi Yoshida prints. Watanabe mon is followed by kanji reading publisher.
M5	1925–1928. Natori Shunsen prints. Reads published by Watanabe. 渡辺工
M6	c.1922–c.1937. Test print, shizuri 試摺
M7	After 1926. Gift or complimentary seal, shintei 進呈
M8	c.1930–c.1936. Special edition seal, tokubetsusen 特別編
M9	c.1935. Watanabe print, Watanabe hanga 渡辺版画
M10	1953–1954. Watanabe print, Watanabe mon and hanga
M11	1957, 1979. Final brush seal, zeppitsu 絶筆
M12	After 1930. Blue stamp on verso.
M13	1970s. S. Watanabe label adhered to verso of prints or frames long after his death.

M1 and M3 may be stamped on the front or verso - often applied to an impression with paper or printing errors, or an artist's proof not included in the count of a limited edition. M6 indicated a trial or proof print. M7 and M8 were applied by Watanabe Shozaburo on excellent examples of certain works that he would then present as personal gifts. May be accompanied by an inscription. M11 indicated Hasui's memorial print. M12 was probably an export stamp, similar to the verso stamp "Made in Japan" that periodically appeared on prints between 1916 and circa 1952. (Stamped country of origin is oft said to be due to the Smoot–Hawley Tariff Act of 1930, but obviously preceded this Act.)

Note 3: Address labels


L1	L2	L3	L4

L1	1916–September 1923 (-Great Kanto earthquake). No. 11 Gorobei-cho, Kyobashi-ku, Tokyo.
L2	November 1925–March 1930. No. 14 Hiyoshi-cho, Kyobashi-ku, Tokyo. 四十町吉日区橋京市東京
L3	March 1930–c.1970. No. 9 Nishi 8-chome, Ginza, Tokyo. 九ノ八西座銀区橋京市東京
L4	c.1970–c.1995. 6-19 Ginza 8-chome, Tokyo. 東京都中央区銀座8-6-19

Diamond-shaped labels adhered to the verso of prints, on folders, or on frames.

Note 4: Pencil signatures

Watanabe pencil signature

Pencil signatures reading Hasui Kawase or English titles were generally applied by Watanabe Tadasu to prints both pre- and post-war. The pictured example matched letters written, dated and signed, by Tadasu in the 1940s.

Hasui did not write in English. A few scarce prints exist with dedications written and signed by Hasui in Japanese.

Note 5: Reproductions

Reproductions with seal J were very well carved and usually result in high quality impressions. In many ways these are superior prints to those with seals I and K that may retain some link to original woodblocks. Those weathered and worn original woodblocks, especially those first issued in the 1920s or 1930s, frequently result in quite poor impressions.

Note 6: Fake and forged seals

Forged seals (pre-war seals on post-war editions)

Unscrupulous dealers are known to forge seals. Fakes of all pre-war seals from A to G have been observed. Their aim of course is to make a print appear older increasing its perceived scarcity and market value.

Prints at the highest risk of having forged seals are those that were in print both pre- and post-war giving a forger a profit maximising opportunity by applying apparently pre-war seals to a post-war edition. The prime example at risk is Hasui's Zojoji Temple in Shiba (1925). In the past 20 years, approximately 1 in 20 Zojoji prints at market had forged seals.

It is recommended to always examine the impression as the difference between an early impression and later impression is usually obvious. Early impressions tend to have clear and sharp lines whereas later impressions from worn woodblocks can be quite blurred in appearance. Early impressions typically featured printing techniques such as baren suji-zuri (baren swirls) whereas later printers favour goma-zuri (speckled printing). A later impression with early seals is not plausible. It has been noted recently (June 2023) by both a Japanese and US source (Egenolf Gallery) independently that the Doi family are publishing later impressions with implausibly early seals.

It is recommended to always examine the condition of an impression. Seal forgers frequently wash toning from a print to obscure its age and usually with an enzyme solution that irreversibly weakens paper. Seal forgers also frequently trim margins and sometimes fray new margins to obscure a print's origin. The paper's deckle is unique to each impression, like a fingerprint.

It is recommended to be sceptical when two seals - double seals - appear on a print. This may be legitimate, however, it was not common and it's possible that a fake seal was added to make the print appear older. Watanabe Shoichiro and the Ukiyo-e Dealers Association of Japan recently warned that Hasui prints were sold in Japan with newly forged seals. The publisher's round seal remained while seals I and K had been erased from the margin and replaced with earlier copyright seals such as C and D (August 17, 2022).

It is recommended to disregard any print entirely with Watanabe seals on a print originally made by another publisher such as Doi Sadaichi.

Impressions missing all publisher seals often sell for significant premiums at auction. These prints were 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 in 1990 for ¥5000 each. Significant premiums at auction require at least two bidders - at least two bidders possibly intending on applying forged seals to profit.

updated September 2025