Dear etaoin: I had a bit of luck. A search turned up words "swaddling clothes" and search for Incunabula swaddling clothes thurned up this:
ncunabula (Latin: swaddling clothes)


Books printed before the end of the year 1500. The term was first used in reference to printing by
Bernard von Mallinckrodt, dean of Münster cathedral, in De ortu et progressu typographicae (Cologne,
1639), a bicentenary celebration of Gutenberg's invention. The author describes the period up to 1500 as
prima typographicae incunabula (the time when printing was in swaddling clothes), a phrase that other
writers soon copied. In the eighteenth century the word incunabula alone began to be applied to the
products of early printing. The singular form incunabulum, now often anglicized or gallicized to
incunable, is used to refer to a single book from this period. The German equivalent is Wiegendruck
(cradle-book). The choice of the year 1500 as the end of the first period suggests a clear break in the
development of printing, an implication that is not confirmed by the work produced early in the sixteenth
century.