THE ROVING EYE.

VELLUM envelopes and invitations aren't new, but the see-through stationery is making a major splash this holiday season.

"It's a big deal," said Janis Flax, whose family owns Flax Inc. stationers in Westwood. "It's been very au courant in the past six months. We keep it in stock because we know the appetite is out there."

The beauty of velum is that recipients can almost see what's inside, but the frosted sheen leaves a little mystery. Borders and sparkles and bold colors are also popular.

The Southwest Museum used vellum envelopes for an invitation to its preview of "Down from the Shimmering Sky: Masks of the Northwest Coast." A striking orange mask shaped like the sun was visible within the envelope.

"There's an opaque feeling -- you see what's behind it and it's a teaser," said Carlyn Greco of the Trammell Crow real estate firm, which recently packaged a vellum information sheet over a picture of a Burbank office project it's marketing.

Marc Friedland, president of L.A. design. firm Creative Intelligence, has long used vellum for marketing material and invitations. "It's a classy look, a simple look, and it makes a big impact when it comes across the mail," Friedland said.

He fears that vellum's growing popularity might be its downfall. "It's unfortunate (vellum) has become a trend, because then it becomes passe," Friedland said. "I hope that doesn't happen."