Green’s Dictionary of Slang

blown-in-the-glass adj.

also blowed-in-the-glass, blown in the bottle
[early glass-blowing often trapped bubbles in the finished object]

(orig. US) genuine, authentic, trustsworthy.

[US]C.L. Cullen More Ex-Tank Tales 56: This is the real dyed-in-the-wool, blown-in-the-bottle —.
[US]J. London Road 125: Truly, Skysail Jack, you were a tramp-royal [...] I take off my hat to you. You were ‘blowed-in-the-glass’ all right.
[US]J. London Smoke Bellew Pt 12 🌐 These is the real, blowed-in-the-glass, wild Indians.
[US]A. Baer Two & Three 3 Jan. [synd. col.] The alco-hallmark of the blown-in-the-bottle souse.
[Aus]M. Garahan Stiffs frontispiece: A ‘Blown-In-The-Glass’ Friend.
[US]Irwin Amer. Tramp and Und. Sl. 31: blowed in the glass.-Genuine; to be trusted. From the old time liquor bottles and other containers, which had the name of the maker or the product blown in the glass to insure the quality.
[US]S.H. Holbrook Holy Old Mackinaw 130: More blown-in-the-bottle logger ballads seem to stem from Michigan and Wisconsin.
[US]J. Steinbeck Sweet Thursday (1955) 127: I tell you she’s a blowed-in-the-glass lady.
[US]Wentworth & Flexner DAS.
J. Steinbeck Travels with Charley (1997) 4: Only when this is recognized can the blown-in-the-glass bum relax.
This Is York 🌐 The 45-year-old Mr Vines was also able to inject into his new job the determination of a blown-in-the-glass sportsman, but more of this later.