Fahrney's Pen Shops. 1418 New York Ave. NW (628-9525) and 111 N. Pitt St., Alexandria (836-2002) .

There was a time when people became attached to their pens, fondled them, cared for them, yes, even had them repaired. Then the age of convenience introduced the disposable pen, too cheap to be repaired, too shortlived to spark feelings of attachment. And there, in the middle, stands Fahrney's Pen Shop, purveyor of pens for 50 years now, trying hard to strike a balance between the desire for the disposable and the nostalgia for comfort and permanence. Still a favorite of anyone who yearns for old-time writing comfort and durability, and an item high on the status-seekers' list, is the Mont Blanc Diplomat fountain pen, with its wide body, 14-karat gold nib and $155 price tag (Farhneyhs is selling it, thoug, for $110 through June). Just across the room from the glass counters with pens like the Mont Blanc are racks of the innocators: pens that light up at night; pens from which perfumed ink flows; ballpoints with multicolored ink; pens that write upside down; pens with felt, razor-thin or chisel tips; "markers" with fluorescent ink; and the ultimate convenience, a pen that writes with erasable ink (not for writing checks, please).Fahrney's also deals in other writing instruments, including the latest in mechanical pencils and calligraphy supplies. CAPTION: Illustration, no caption