''They say that doing an architectural rubbing is as easy as pie,'' mused the New Yorker as she knelt in a Manhattan church, vigorously pushing a piece of graphite over some white paper.
The woman was part of an enthusiastic group busily ''lifting'' rubbings off some handsome Moorish floor tiles. They were being guided in their new-found craft by Cecily Barth Firestein, a New York artist who teaches the art form and has made it a vital part of her own career.
''Doing a rubbing really is a simple process,'' the woman concluded as she got to her feet, ''but it does take some practice to develop the right hand pressure and to get just the right feeling for what you are doing. But what a delightful experience!''
A moment later she added, ''This has given me a whole new idea for projects I can do with my grandchildren this summer in Maine.''
This convert to a new hobby and her friends had earlier heard Mrs. Firestein explain the history and fine points of lifting rubbings from architectural details, archaeological carvings, tombstones, manhole covers and other industrial elements. They had watched her demonstrate how to reproduce an interesting carved surface by placing a piece of paper or cloth over it, and rubbing or dabbing with such media as colored waxes, inks, or graphite.
Over the past 13 years Mrs. Firestein has helped revitalize this ancient method of documentation, which began in China, then moved to Japan, Cambodia, Thailand, Europe, and the rest of the world. She has taught hundreds of people how to lift rubbings, from eager five-year-olds to fascinated octogenarians. By taking groups to a variety of interesting sites to do their rubbings, she has helped people discover the architecture, history, and peculiar art forms of New York City.
It is this new awareness, this new way of looking at things and at what they mean, that is so valuable to people, says Mrs. Firestein.
''Our projects teach children, especially, to open their eyes and see architectural details and other things artistic and beautiful that they would normally never notice,'' she says. ''Producing rubbings makes them more conscious of all the different textures in their lives. They feel the texture of stone, fabric, tile, embossed leathers, wallpapers, bricks, wood, brass, and concrete.''
Her first workshop in rubbing was for parents and their children, and Parsons School of Design will offer a similar class this coming fall. ''It is a wonderful craft for parents, or grandparents, to do together with children,'' the artist says, ''for a child can do fully as well as his parent or grandparent. There is no sense of competition, just a sense of adventure and fun.''
She directs her students' attention to the abundance of rubbable objects that are always nearby, such as wrought-iron window guards, numerals over a doorway, raised surfaces on church facades, letter boxes, elevator doors, and plaques in the pavement. And she says that doing rubbings while they are traveling anywhere in the world means they can always bring home unique souvenirs of their trips.
The favorite location for doing rubbings in New York City is probably the Cathedral of St. John the Divine in upper Manhattan, the artist says, though she thinks the Art Deco elevator doors at the Waldorf Astoria hotel are special, too , and that old movie theaters of the '20s and '30s are full of intriguing designs. Sometimes she herds her groups onto a subway and takes them to Woodlawn Cemetery to rub a few century-old gravestones, but she can also be seen with her entourages busily working at sites in all five boroughs of New York.
Mrs. Firestein is an accomplished and versatile artist who has just had her 15th one-woman show as an artist-printmaker at the Phoenix Gallery in Manhattan. She has, since 1962, exhibited oil paintings, painted wood constructions, etchings, collages, color intaglios, and monoprints.
Her own original work is included in museums, as well as corporate and private collections. She holds degrees in art education from Adelphi University and from New York University.
Mrs. Firestein has conducted ''city rubbing workshops'' for numerous city institutions. In 1974 she received a grant from the Preservation League of New York State to lift rubbings from all grave markers in three cemeteries of the Spanish-Portuguese Synagogue, dating back to 1630. Since then she has worked with many historical societies and taught members how to document their local landmarks by means of rubbings.
She has also written a paperback book, ''Rubbing Craft,'' which can be ordered directly from her at 8 East 96th Street, New York, N.Y. 10028 for $5.95 postpaid.
Mrs. Firestein explains in her lectures, and also in her book, how rubbings can also be translated into patterns for needlepoint, latch-hook rugs, stencils, silkscreens, jewelry, T-shirts, pillows, and the like.