George Delacorte founded Dell Publishing Company as a pulp house in 1922 and started producing paperbacks in 1943. The first titles were mostly mysteries with those well known air-brushed covers by Gerald Gregg. Dell #5 was the first to have a map related to the action on the back cover, and thus were born the now famous "Mapbacks". Almost all Dell books published until 1951 had mapbacks, when the practice was gradually abandoned. By the mid 1950s all publishers were embracing a more realistic style of cover art, led by James Avati at Signet. Many of Dell's later covers were the work of Robert Stanley using himself and his wife for models. Fools Die On Friday is one of their better know covers, mostly because it was censored and re-issued with a more modest cover. Both are easily recognizable on many covers which gave Dell a feeling of sameness for several years.
Still, most collectors have a keen sense of appreciation for Dells, and they are probably the most collected Vintage Paperbacks.