SINCE THERE are many forms of illustration, we call what we do editorial illustration. That is to say, we illustrate stories, plays and articles for books, magazines and newspapers. When describing a creative process, people often use words like "magic" and phrases such as "born with talent." Such mysterious qualities may be part of the process, but so are years of observation and work mastering techniques and various media. We learn rules of design and composition that are absorbed and even forgotten, only to find them resurfacing as "instinct" when we move a line slightly and feel it is where it should be.

Cliche's such as "art is fun" or "I love what I do" are often misinterpreted as "art is easy"; but anyone making a living as an illustrator works long hours, works on weekends and holidays, and leads a fairly isolated life. Still we love what we do.

The first step in illustrating a book is studying the manuscript. Our editor may call to discuss a story briefly and later send it to us, or we might receive a manuscript though the mail. After reading the story, we decide if it is something we want to do. We choose particular stories for different reasons. One may carry an idea or message we feel is important. At other times the challenge hooks us. For instance, a story like Hundred Penny Box (by Sharon Bell Mathis), that consists mostly of conversation in one room offers little in graphic terms. In a case like this, we must concentrate on subtle feelings and expressions. On the other hand, some texts such as Verna Aardema's Why Mosquitoes Buzz in People's Ears, are full of graphic images and, if the story is great too, it's hard to say no. Fantasy, such as Michael Patrick Hearn's The Porcelain Cat, gives us more freedom since we have a chance to create something that doesn't exist.

After accepting a manuscript we go through the business of contracts and negotiations, discussing with the publisher the book's size, number of pages and whether to use color or black and white. Next, we read and re-read the manuscript, deciding where to break the text on each page for the best graphic images and flow of action. At this point, we usually start to get a feel for whether the type should be light or heavy and talk over several typefaces with the publisher's art director.

The art director next sends the type -- set to the agreed-upon size and width of columns -- on a galley form. We cut up the galley and tape the copy on each page of a dummy -- a hand-made book with the same size and number of pages as the actual book -- to give us a feel for how the story moves from page to page. We then start work on the design of the page, deciding early on whether we want a border or not. Sometimes, a text like Margaret Musgrove's Ashanti to Zulu, requires each picture to be complete within itself. A border helps to accomplish that. At other times a story -- such as Verna Aardema's Rabbit's House -- should flow from page to page with no break, so we carry the art to the edge of the page (called a bleed).

If a manuscript requires research, that process starts now. Often we can draw on our own collection of books and files. We also do extensive research at libraries with the invaluable assistance of librarians.

During this conceptual stage, the two of us toss ideas back and forth, sometimes for days. One idea sparks another. For us brainstorming is a definite advantage. When we get equally excited over an idea, we know it's right. We feel it is our job to read between the lines, to restate the story in graphic terms rather than confining ourselves to the words.

At this point we roughly sketch in the dummy, working out the sequence of events and the composition. In a picture book, such as Brother to the Wind (by Mildren Pitts Walter), we have page after page to build images, to show time passing, to include little idea stories, to create a world. We become familiar with the characters and imagine how they feel and how they might react. It is very personal because we project our feelings into the work.

After the dummy is shown to, and approved by, the publisher, we begin tight pencil drawings, usually the same size or scaled "half up" (that is, 1 1/2 times the final printed size). At this stage, all the details are worked out. We draw on a heavy vellum tracing paper that can withstand erasing and correcting.

These pencil drawings are sent to the publisher, whose editors check for mistakes and inconsistencies of any kind. When the "pencils" are returned, we start the finished art. The drawings are traced down onto a surface appropriate to the medium we want to use. Water colors call for special watercolor paper, or we might use acetate for acrylics. Since we don't always work in the same technique, we might do one or two trial illusrations first.

Once the technical problems are solved, we begin on page one and work in sequence. This way, we can keep up a continuity in color, suggest the gradual passing of time, and maintain the even flow of the story.

Depending on the detail and the technique, a book will take from three to six or more months to complete, as in the case of The People Could Fly, by Virginia Hamilton. When the art is finished for a picture book, we mount each illustration on a board to protect it and use our bookbinding skills to construct a box to hold all the work. Each project has its own custom box for storing the art; this ensures that everything is kept together when the book is sent from the publisher to printer and back.

It is always exciting to receive the finished book, to hold and look through page by page. At this point, months have passed and we are into other work, so we see the book and its art with new eyes. Sometimes, we're pleased . . . sometimes we see things we could have done better.

We do hope people of all ages enjoy our work. After publication a book, like a child, is out in the world with a life of its own. We watch its progress -- through reviews and royalty statements -- to see whether it's getting along well or not.

Since illustrating a picture book is a long process, we also take on book jackets and single illustrations, both to help the cash flow and for a change of pace.

A book jacket requires reading the manuscript, noting details and marking possible scenes to illustrate. Unlike a picture book that provides page after page to tell a story, a dust jacket must find the essence of a book and sum it up in one illustration. Sometimes one scene will say it all -- at other times it may be a number of elements combined that give a symbolic statement of the book's overall feeling, as in many of our covers for Harlan Ellison's short stories.

Book jackets take at least two weeks from reading the manuscript, research, drawing, to finished art.

If asked to sum up our career, we both would say that cultural understanding and diversity have been its theme. We have illustrated Native American stories and poems, African tales, Arabic stories, novels of fantasy and magic. Our next book is based on a Greek myth and the one after that will be a Chinese fairy tale.

Although there are difficult periods -- getting an idea, technical problem-solving and living from deadline to deadline -- we have the satisfaction of feeling that we are accomplishing something important. We have challenge, variety and meaning in what we do. It's a good life. :: Leo and Diane Dillon have received many awards for their illustrations, including the Caldecott (twice) for their picture books and the Hugo for their science fiction cover art.