With all the 1986 stamp catalogues now published, it is a good time to take a look at are essential to intelligent collecting.

This is the first year under a new publisher for the four-volume Scott Standard Postage Stamp Catalogue and the one-volume Scott Specialized Catalogue of United States Stamps. Scott is, in fact as in title, the standard, because the number applied to a stamp in the Scott catalogues is used by virtually all American dealers and collectors in referring to that particular stamp.

The catalogues and all the other Scott publications were purchased by Amos Press, cations are now produced in Sidney, Ohio, instead of New York. Amos Press puts out the weekly Linn's Stamp News and various other philatelic and numismatic publications.

Each of the four volumes is more than 100 pages longer than last year's, and the Specialized, as it is popularly known, has an additional 20 pages, but the price is still $20 per volume. The catalogues are often discounted by local dealers.

The stamp market operates like any other free market, but unlike the big financial markets, there is not enough activity to make it profitable to put out even monthly, let alone daily, quotations. Catalogues publish prices once or twice a year, using the latest data available, which works out all right when prices remain steady. When the market is volatile, the catalogue prices become out of date quickly.

Catalogue prices are therefore used as guidelines. During a boom stamps tend to sell well above catalogue listings. In bad economic times, stamps tend to sell at substantial discounts from catalogue values. In addition, there are always variables such as the condition of a stamp, or a dealer using an issue as a loss leader.

The catalogue publishers stress their principal selling point, price fluctuations from year to year. This is significant to anyone whose main concern is prices or new issues. But most collectors do not and should not buy new catalogues annually. The average collector buys a new catalogue every three to five years, according to surveys.

The four volumes of the Scott Standard catalogue contain more than 1,100 pages. Volume 1 covers the United States and territories, Canada, Great Britain, British Commonwealth countries and the United Nations. The other three break down the rest of the world alphabetically.

The Specialized, which comes out six months later than Volume 1, has almost 900 pages and highly detailed reference and pricing information on regular and airmail stamps, blocks, covers, stationery, revenues, Confederate stamps, American possessions and trust territories and the United Nations. A number of modern U.S. errors are listed but not priced.

For collectors of first-day covers, the Washington Press has put out the 51st edition of its specialized catalogue of American first-day covers, a 124-page compendium with full data about each cover. In addition to hundreds of price changes and new listings, a listing of presidential inaugural covers has been introduced, and the section for official first-day ceremony programs has been enlarged.

There is also an extensive section of postmark varieties, United Nations covers and pricing data. The book is available at stamp dealers for $3.50 or directly from the publisher, The Washington Press, 2 Vreeland Rd., Florham Park, N.J. 07932, for that price plus a 50-cent charge for shipping.

The Scott 1985 U.S. First Day Cover Catalogue, with pricing guide and inventory checklist, edited by Michael A. Mellone, is a pocket-sized paperback published by Barnes & Noble, with a profusion of illustrations on its 155 pages. It sells for $3.50.

Stanley Gibbons of Britain publishes the Simplified Catalogue, Stamps of the World in two volumes. It is a bare-bones listing of stamps, replete with illustrations.

Stanley Gibbons has also issued catalogues for collectors who specialize in the stamps of particular countries.