Is the usage of word, “Deck” as a package of paper limited to cards?

Solution 1:

If embarrassment belongs anywhere, it belongs with the publishers of the dictionaries, not with you. Century Dictionary and Cyclopedia, found at Wordnik, includes this definition:

deck n. A pile of things laid one upon another; a heap; a store; a file, as of cards or papers.

In short, you were using the word legitimately.

Solution 2:

Here are the fifth and sixth senses from the OED entry (note that the latter is considered "dead"). I don't think that the usage you are proposing is too far-fetched. It's just too localised to make it into the dictionaries. If you have some textual citations you might consider sending a letter to OED, as they are always on the lookout for missing words.

5.
a. ‘A pack of cards piled regularly on each other’ (Johnson); also the portion of the pack left, in some games, after the hands have been dealt. Since 17th c. dial. and in U.S.

1594 Selimus sig. F4v, If I chance but once to get the decke, To deale about and shufle as I would.
1594 R. Barnfield Shepheard Content viii. sig. Eiij, Pride deales the Deck whilst Chance doth choose the Card.
1595 Shakespeare Henry VI, Pt. 3 v. i. 44 But whilst he sought to steale the single ten, The king was finelie fingerd from the decke.
1609 R. Armin Hist. Two Maids More-clacke sig. D1v, Ile deale the cards and cut ye from the decke.
1701 N. Grew Cosmol. Sacra i. iii. §21 The Selenites [have the shape], of Parallel Plates, as in a Deck of Cards.
1777 J. Brand Observ. Pop. Antiq. (1849) II. 449 In some parts of the North of England a pack of cards is called to this day..a deck of cards.
1860 in J. R. Bartlett Dict. Americanisms (ed. 3)
1882 B. Harte Gentl. La Porte in Flip 135, I reckon the other fifty-one of the deck ez as pooty.
1884 R. Holland Gloss. Words County of Chester (1886) , Deck o' cards, a pack of cards.
1885 Cent. Mag. 29 548/1 An old ratty deck of cards.

b. A packet of narcotics; a small portion of some drug wrapped in paper. U.S. slang.

1922 E. F. Murphy Black Candle (1926) i. v. 52 Small paper packages [of cocaine]..are called ‘decks’, and contain about a couple of sniffs.
1927 Flynn's 9 July 462/2 At night it was ‘snow’ that went over the counter..to poor devils who left behind them three dollars..for a deck.
1949 ‘J. Evans’ Halo in Brass (1951) iv. 29 A deck of nose candy for sale to the right guy.
1966 C. Himes Heat's On iii. 27 When it's analysed, they'll find five or six half-chewed decks of heroin.


†6.
a. A pile of things laid flat upon each other.

1625 F. Markham Bk. Honour ii. vi. 63 Any whose Pedigree lyes so deepe in the decke, that few or none will labour to find it.
1631 J. Mabbe tr. F. de Rojas Spanish Bawd xix. 185 Subtill words, whereof such as shee are never to seeke, but have them still ready in the deck.
1634 R. Sanderson Serm. II. 287 So long as these things should hang upon the file, or lie in the deck, he might perhaps be safe.
1673 A. Marvell Rehearsal Transpros'd II. 394 A certain Declaration..which you have kept in deck until this season.

b. Part of a newspaper, periodical, etc., headline containing more than one line of type, esp. the part printed beneath the main headline. Also attrib.

1935 H. Straumann Newspaper Headlines i. 28 These are first decks (and streamers) only.
1935 H. Straumann Newspaper Headlines iii. 87 The first three lines or ‘decks’ as they would be called in present-day journalism.
1965 L. H. Whitten Progeny of Adder (1966) 127 The eight-column headline told him of Pantelein's body being found. But it was the ‘deck’ headline that held him: county coroner cites ‘vampirism’.

Solution 3:

"Deck" is a common term in news style writing:

Subhead (or dek or deck)
A phrase, sentence or several sentences near the title of an article or story, a quick blurb or article teaser.