by Karen Schafer | Staff Writer

What's up with these colored pencil people? Are they something else, scratching out thousands of pencil marks, producing layer upon layer, with some drawings taking upwards of 400 hours to complete? One colored pencil artist, preferring anonymity, calls the group ''control freaks" and maybe a little ''obsessive." One painter suggests that colored pencil artists surely must have clean houses and even cleaner fingernails.

As for the folks trekking through the 15th annual CPSA International Exhibition on view in The Mansion at Strathmore in North Bethesda through Aug. 25, many just stop and stare in disbelief at the shimmering watermelon slices and the photo realistic portraits.

It seems that all this layering causes the works to develop a natural sheen making works like James Mateer's ''On the Rocks with Two Olives" look as if the glass is sweating actual water droplets in all its effervescent glory.

The competition was keen, with some 686 entries and only 120 accepted. Deciding who was in and who was out wasn't easy for lone juror Ross Merrill, who by day is the Chief of the Conservation Division of the National Gallery of Art in Washington, D.C. He spent hours sitting in a darkened room peering at slides. It was Merrill's job to ignore bad framing techniques and imagine the actual size of the work since all the slides were larger than life.

Once Merrill made his choices and the works were sent to Strathmore, he then decided who would win the 18 cash prizes ranging from $300 to $1,500. While the juror was impressed by the ''high quality" of this year's submissions, he confesses to an occasional mistake. After all, sifting through slides isn't an exact science; subtle work often is shut out by bolder, brighter submissions.

With no particular theme to work from, Merrill was most interested in the quality of the subject matter and attempted to avoid anything that seemed trite.

''I look for those that give new insight into the visual image," but he concedes this can be tricky since we are bombarded with images everyday. He avoided the overused ocean scenes and quaint farmhouse motifs, but accepted a couple of magnificent flower arrangements

''Uplifting" also was on his agenda. Nothing even remotely controversial or political sullies this show. Instead, it is filled with beautiful objects that, but for a handful, immortalize a simpler time full of radiant horses, verdant landscapes, glistening Christmas ornaments and fascinating faces.

And while absolute realism rules, Eugene Hammiel of Fort Washington was ecstatic when his abstract ''Southampton Dunes #1" was accepted into this international exhibit. After years of working in charcoal, once the artist started working in colored pencil, he ''fell in love." Hammiel is taking the medium to a new level, creating images on both sides of the translucent Mylar paper, explaining ''I push and pull and saturate the paper with color."

It is this kind of innovation that is taking this medium from child's play to fine art.