IN Turkey where it flourished in the 15th century, marbled paper making was known as ebru, or the art of the clouds.
Pastel, abstract and as mutable as a cloud, marbled paper was reserved for religious writings because it so enhanced the venerable texts. Islamic law forbade its ripping, burning or otherwise unauthorized disposal. Marbled paper, in fact, was sacred.
In 17th-century France the official bookbinder to Louis XIII created a similar papier a cuve, so-named for the basin, or cuve, in which the paper was dipped to obtain its heavenly hues. Colorful yet dignified, marbled paper was used for the windy tracts that were issued in the sovereign's name. It was paper fit for a king.
And over the seas in shrewd Yankee America, Benjamin Franklin insisted in 1776 that the $25 bill of the new Revolutionary currency be edged with inimitable marble paper to prevent its being forged.
Although marbled paper, like nearly everything civilized, probably originated in China and a comparable paper art called suminagashi has existed since the 12th century in Japan, ebru arrived in Europe through Venice with its windows open to the Orient.
The tight, stylized, characteristically Islamic interplay of form and color made marble paper ideal for the flyleafs of leather-bound, handwritten books. With the invention of the printing press and the diffusion of cheaper texts, marbled paper effectively constituted the first paperback revolution when it jumped from the inner to the outer covers of books.
Made throughout Europe even in the 19th century, marbled-paper making survives today almost exclusively in Florence with its old artisan economy grafted onto the airborne tourist trade of the 20th century. Nothing is lighter or easier to take home than a sheet of handmade carta marmorizzata, which sells in Florence's three main marbled paper shops for less than $8. Cheaper still are the pencils covered decoratively in marbled paper and selling for little more than $1 at Giulio Giannini & Figlio, Florence's oldest marbled-paper maker at 37r Piazza Pitti, across from the palace of the same name.
Founded in 1856, Giannini was first a bookbinder that catered to the large foreign literary colony that reigned over 19th-century Florence. Elizabeth Barrett Browning, for one, had her ''Sonnets From the Portuguese'' and ''Casa Guidi Windows'' published in later editions by Giannini. Browning's Florentine home, the Casa Guidi, is now a museum at No. 8 Piazza San Felice, just around the corner from the Giannini shop. The bottega celebrated its 130th anniversary last year with an unusual book exhibition in the prestigious Palazzo Strozzi.
It was the English pre-Raphaelite revival with its fascination for illuminated Gothic manuscripts, particularly the flowery first letter, that was the inspiration for Florentine paper, which is machine made, widely sold and not to be confused with marbled paper.
''There's not a single Italian text on the subject, although most marble paper is now made in Florence,'' said Gabriele Giannini, 43, who runs the cheery shop that looks rather like a children's nursery with its prevailing pastel, marbled-paper colors. A typical artisan family operation, the shop is run jointly by Giannini's brothers Guido and Enrico under the direction of their father, Giulio, 86, who illustrates the poetry the Giannini still publish in Italian and in English.
''The English are the true book lovers of the world; the French are the finest connoisseurs,'' continued Gabriele Giannini. ''Do you know that in Paris there's a Society of Friends for the Binding of Books? This is unheard of in Italy.''
Quintessentially Italian and unchauvinistic, Giannini gallantly nominates the French company Michel Duval as the best marbled paper maker today. The reason, he says, is Duval's faithful use, like his own, of natural dyes and water to marble paper. The competition, he said, even in Florence often uses chemical dyes and oil to create the swirling, rhythmic patterns that have enchanted the human eye for nigh on 2,000 years. While it's easier to use oil rather than water as a blender, oil tends to fuse and muddy rather than clarify the colors, explained Mr. Giannini.
Thereafter, marbling is a secret best known to its jealous master. It's the reason little has been written on the subject. Basically, a resin or glue is added to the basin initially to attach the floating pigments to paper. (The Gianninis boil lichens from the North Atlantic to make their glue.) After the colored paper is lifted gently from its bath, it is patted, sponged, combed or brushed into patterns. The three most popular are peacock's tail, combed or marbled; the last became the general term early on. Of the 200 or so sheets usually obtained from one basin, no two are ever alike. Each is a work of art that can then be cut and glued to agendas, blotters, bookends and all the paraphernalia to enhance desks and the even more elusive art of writing.
Prices in the Giannini shop range from about 50 cents for a bookmark to about $300 for a photo album. The most popular items are the address books and agendas selling from $7 to $18 according to the size. In addition, there are the purely decorative spheres, pyramids and obelisks at about $60. Giannini even makes portable or lap desks in the same pattern as accessory objects for about $240. They are perfect for writing in bed.
THE current revival of the ancient art of marbling inspired Lino Previato, 56, to leave Giannini five years ago and set up shop on his own. At La Bottega Artigiana del Libro, 40r Lungarno Corsini, he specializes in the bookbinding that he was taught as a boy by the Salesian monks of Turin. Perhaps the most ingenious items in his shop are the empty box-books, beautifully bound in leather and finished in marbled paper, which look scholarly and impressive on a bookshelf. They are also useful containers of letters, bills, snapshots, souvenirs and all the paper that clogs the average home.
Mr. Previato, who uses both oil and water-based colors in his basin, makes all the regular agenda and address books. The most fanciful of his works are the carnival masks made of papier-mache and covered with marbled paper or marbled directly. They sell from $25 to $45. Another offshoot of the old Giannini bottega is Il Papiro, or The Papyrus, the reed with which the ancient Egyptians made paper. Founded by another Giannini brother, Francesco, 39, in partnership with Cianni Parenti, Il Papiro has branches in Siena, Rome and Venice as well as two shops in New York. Generally the prices are cheaper and the choice greater in Florence. The main and original Il Papiro shop is at 55r Via Cavour, the others at 24r Piazza del Duomo and 42r Lungarno Acciaiuoli. Generally, Il Papiro's colors, whose recipe was not given for publication, are darker, giving the shop the air of a stately library.
AT Il Papiro the characteristic items are the folded paper animals, or origami, first made by the Japanese and re-invented by Il Papiro a few years ago. While these delightful frogs, owls, peacocks and butterflies would seem to be esthetic toys for adults, they have an effect on children, too. A certain, irrepressible 3-year-old nephew by the name of Craig became so attached to his yellow and brown cricket from Il Papiro that he took it out with him to shovel snow last winter. Not surprisingly, it disappeared into the blowing drifts. The loss was so great that an urgent appeal was made to Florence to send another marbled paper cricket. It cost his aunt about $5.
In addition to blank books for writers, Il Papiro offers ones with musical staffs for composers. They retail from $30 to $40. The most expensive item in the shop is the life-size wooden cobra dappled with marbled paper for about $375. There is also a choice of writing notes and paper in boxes selling for around $15.
In the early 70's, the Gianninis were the first to cover desk objects with marbled paper. That started the revival. Now, they are covering the same utilitarian items with some of the less important pieces of paper in which Florence floated after the 1966 flood. Salvaged, restored and applied by the Gianninis, they are reminders of the value of paper before the throw-away society and worse, before the ballpoint pen, which seems to have destroyed penmanship. ''In the old days, writing with a quill pen on fine paper was almost an art in itself,'' said Gabriele Giannini. ''Now people can appreciate this daily by using our document-covered diaries and address books.
The competition has caught on, he added, ''But with photocopy editions.''
All shops mentioned are open without a midday break from 9 A.M. to 7:30 P.M. Monday through Saturday. On Sunday, Il Papiro is open on the Via Cavour from 9 A.M. to 1:30 P.M. and in the Piazza del Duomo from 10 A.M. to 6 P.M. All owners promise delivery anywhere in the world.