The New York (NY) Evening Graphic had a brief run from 1924 to 1932, but it was known for its high circulation in the city and its sensationalism, such as stories of murder and photos of the human figure. The Evening Graphic acquired its popular nickname of Porno Graphic (also porno-Graphic) by at least 1925.
 
   
Wikipedia: New York Graphic
The New York Evening Graphic (not to be confused with the earlier Daily Graphic) was a tabloid newspaper published from 1924 to 1932 by Bernarr “Bodylove” Macfadden. Exploitative and mendacious in its short life, the “pornoGraphic” defined tabloid journalism, launching the careers of Walter Winchell, Louis Sobol, and sportswriter-turned-television host Ed Sullivan.
   
Google Books
The Reader’s Digest
Volume 4
1925
Pg. 490:
In the meantime, Bernarr MacFadden started an afternoon daily, the Evening Graphic, which, except for its size, was unlike either the Mirror or the News. A member of the Newspaper Club promptly dubbed the new paper the Porno Graphic.
 
3 April 1931, Fitchburg (MA) Sentinel, pg. 6, col. 2:
Bernarr MacFadden has bought Liberty magazine. Faced with the possibility that the weekly may be remodeled after the New York porno-Graphic, the reader may take refuge m the thought expressed by Walter Lippman in his recent review of the tabloids, “When everything is dramatic, nothing is dramatic.”
 
Google Books
Imperial Hearst:
A Social Biography
By Ferdinand Lundberg
New York, NY: Equinox Cooperative Press
1936    
Pg. 294:
In 1925 Bernarr Macfadden, publisher of True Stories and bogus health periodicals, started the Evening Graphic, which newspaper men quickly dubbed the Porno-Graphic.
 
Google News Archive
19 March 1941, Milwaukee (WI) Journal, “Athletic Mr. MacFadden Retires” by Kirk Bates, pg. 12, col. 6:
MacFadden’s most lurid adventure in publishing was his tabloid newspapers, of which he once had eight, chief among them the Evening Graphic of New York. The paper, going in heavily for pictures, specialized in legs, love nests, bosoms and murder. New Yorkers promptly dubbed it the “Pornographic” and it was never a success, the circulation being good enough but a poor medium for advertising.
     
Google Books
Briton Hadden:
A biography of the co-founder of Time
BY Noel F. Busch
Westport, CT: Greenwood Press, 1975, ©1949.
Pg. 203:
On the contrary, he gave further aid and comfort to Time by running a second editorial in which he expressed curiosity as to how much the publisher of a now defunct tabloid, the New York Evening Graphic, thought Time was helping him by referring to this as “the Evening porno-Graphic.
 
Google Books
American Chronicle:
Six Decades in American Life, 1920-1980
By Lois G. Gordon and Alan Gordon
New York, NY: Atheneum
1987
Pg. 68:
The tabloid market expands; Bernarr Macfadden’s True Story gains a circulation of 2 million with stories such as “The Diamond Bracelet She Thought Her Husband Didn’t Know About”; many call the Evening Graphic the “Porno-Graphic.
 
Hartford (CT) Courant
Chapter Five: After Roaring 20’s, A Great Depression
By JOSEPH F. NUNES,
Special to The Courant
OCTOBER 18, 2014, 4:48 PM
(...)
Gauvreau was scooped up by the publisher of the New York Evening Graphic, a sensationalist tabloid soon nicknamed the Porno Graphic. There he helped launch the careers of gossip columnist Walter Winchell and sports editor Ed Sullivan, the future TV showman who a few years earlier had been a fledgling sportswriter at The Hartford Post before it folded.