Did you know that a single, high-quality picture "envelope," assembled to protect fine art, could easily cost $3,000 or more? By "envelope," we mean the frame, the glass, the mounting board, the mask (or border) and the craft paper backing.

A high-end antique picture frame by itself, without all the other elements we just mentioned, could cost hundreds of thousands of dollars.

Fortunately, you don't have to spend anywhere near those amounts to get your favorite photograph properly mounted and sealed. All you really need to do is read on.

The element that causes a framed picture to be expensive is the frame. Barring that particular cost, the rest of the row is truly "easy to hoe." All you have to do is to know where to look and what to buy.

Other than a reasonably priced frame ($25 to $200), here are the elements you will want to consider to ensure best presentation and long-lasting quality:

--Cover glass.

--Mask or border.

--Backing or dry mounting.

--Craft paper backing.

--Dated labeling.

--Security picture hanger.

Glass really is important. Not the regular kind -- the museum quality kind; the kind that filters out ultraviolet light that fades things. Good glass will not distort the image that it protects and when slightly etched it reduces unwanted reflection and makes the artwork easier to look at.

Borders and masks can add to the impact of a piece of art by contrasting, highlighting or accenting certain colors within the artwork. White and off-white cardboard and cloth borders are most common. However, colored borders and those with texture can add great interest to a presentation.

Be careful here. Fancy borders can get as expensive as fancy frames. Be creative. Try using a material for your border that accentuates the picture. You can use dried leaves for a landscape or cloth from apparel worn in the photo. The possibilities are endless.

Photos have a tendency to curl and buckle with age. This can be prevented by "dry mounting" the photo to cardboard. Dry mounting takes special equipment, but is inexpensive to do. A piece of heat-activated adhesive is sandwiched between the back of the photo and the front of the cardboard. The conglomeration is placed in a heated press for about 30 seconds and the three layers are bonded to become one "sturdy" photo.

Contact your local photographer for price and availability.

Even if you do not intend to dry mount your photo, be sure to back the artwork with mounting cardboard. This will give the assembly stability.

With the glass, the artwork and the backing in place, all can be bound to the frame with brads, glazing points or the connector of your choice. Keep in mind that it is better to use more retainers than fewer.

Nearly last but not least is the seamless piece of craft paper backing that is used to seal all from the rest of the world. Hey, who wants a dusty photo just because the back of the frame wasn't properly sealed?

With the frame laid on a table and with the back of the frame facing up, apply double-sided tape all the way around the back. Next, lay the seamless paper in place and burnish it at the tape joint for a good tight seal.

Finally, make a label on your computer. The label should date the art and explain everything about it. How many times have you looked at old, old photos and no one knows who's in the picture? Someone knew once.

Keep in mind that there can be more to hanging a picture than a wire and a nail. Hotels and motel owners purchase special hanging devices that are relatively easy to install and will hold a picture absolutely straight and true even in an earthquake. If you decide to use a conventional wire and hanger, at least be sure to use silicone or rubber bumpers at the two bottom rear corners of the frame to reduce movement.

Now sit back and enjoy your masterpiece.

And, that's all there is to it.