Framing tips on hardware may not seem exciting, but understanding the function and limitations of various types of screws, hangers, and wires will ensure that your framed drawings and paintings are properly supported when displayed. Take a little time to tackle the terminology and technicalities. Your art deserves nothing less.
Framing Tips: The Skinny on Screws
The most basic piece of picture-hanging hardware is the screw, the size of which is based on shaft dimensions (gauge) and threading. To simplify the identification of smaller, more commonly used screw gauges, a numeral designation preceded by a crosshatch symbol (#) has been adopted, with #0 being the smallest and #15 the largest. The most commonly used screw gauges in framing are #4, #6, and #8.
Wood screws (A-1) have a coarser pitch (fewer threads per inch) than sheet metal screws, and often the shafts of wood screws are unthreaded just below the head. Because there are no threads to catch the wood along the smooth portion of the shaft, a wood screw can pull one piece of wood flush against another. Metal screws (A-2, above) have sharp threads that cut into materials such as sheet metal, plastic, or wood. They make excellent fasteners for attaching metal hardware to wood and are preferred for this use because of their fully threaded shafts.
There are many head styles for screws, with flat head, pan head, and round head being the most common for framing. When countersinking (inserting a screw so the head is flush with the wood surface), choose flat-head screws. Round-head screws have a domed shape, and pan-head screws have a slightly rounded head with short vertical sides. There are also many drive configurations, but straight-slotted, Phillips, and a combination of these two are most common (B).
Why all this talk about screws in an article on framing tips? For one thing, you generally need them to fasten picture-hanging hardware to a frame, which leads us to our next topic.
Framing Tips: Dependability of D-Rings
D-rings, whether of the single-hole, two-hole, or strap-hanger variety, are an excellent choice of picture hanger (see C-1, C-2, and C-3).
When installed with #4, #6, or #8 pan- or round-head screws, D-rings lie flatter against the wall than screw eyes (a popular but poor choice of hanger—more about those below). You may position single-hole D-rings to match the 60-degree angle recommended for hanging wire; D-ring strap hangers usually end up at an angle more vertically oriented.
Heavy-duty D-rings and strap hangers, constructed of doubled steel, are intended for hanging heavy wood frames, large gallery wraps, or cradled boxes, and you can use them with or without picture wire. When using them without wire, align the D-rings or strap hangers vertically at the upper corners on the back of the frame. Then suspend the picture directly on substantial picture hooks or screws anchored into the wall.
Framing Tips: Strengths of Steel Plates
Another excellent choice of picture hanger is the Super Steel Hanger (see E-1 and E-2). These are steel plates with either two or four screw holes located both above and below a ring, to which you attach the picture wire.
A four-holed, steel-plate hanger easily supports a frame of up to 100 pounds, while the shorter two-hole style holds up to 50 pounds. Mount the center of this hardware one-quarter of the way down from the top edge of the frame, either centered on a narrow moulding or about ½ inch from the inner edge of a wider moulding. Use #4 or #6 screws.
Framing Tips: Hazardous Hardware
Sadly, the two most popular types of picture-hanging hardware aren’t the strongest or most effective. Consider the following cautionary framing tip before grabbing a sawtooth hanger (D-1) or a screw eye (D-2).
A sawtooth hanger is a jagged-edged, metal strip, 1 to 2 inches long (D-1). It’s popular because of its simplicity and the ease with which it can be installed, but it has a high failure rate. This is not the result of weakness of the metal strip, but rather of the softness of the frame moulding and selected fastener.
Most sawtooth hardware comes with short 3⁄8– to ½-inch tacks that press into the wood of a painted panel or frame. If the wood is soft—like pine—nails can pull out of the frame due to the weight of the framed work and the pull of gravity. Substituting small #3 screws for the tacks greatly improves the holding strength. Snap-in sawtooth hangers, used with metal frames, require no screws and won’t pull out. Even at their best, however, sawtooth hangers should never be used for hanging fine art because a picture can easily be knocked from the sawtooth. Galleries generally don’t accept framed art with sawtooth hangers of any kind.
A screw with an eye (looped head) and shank is called an eye screw, eye hook, or screw eye (D-2). It’s designed to be an all-in-one piece of hardware; you screw one end of it into the back of a frame, and you attach the hanging wire to the other end. Screw eyes are the most popular type of picture-hanging hardware; however, they create problems.
Installing screw eyes into hardwoods such as maple, oak, or walnut creates stress at the point where the screw meets the eye, thus weakening the hardware (D-2). If you select a screw with too small an eye for the hardwood of your frame, the eye can break from the shaft during installation. What’s more, when inserting a screw eye into soft or reconstituted wood, such as medium-density fiberboard (MDF), the threading, rather than grabbing onto the wood grain, can create sawdust. This allows the screw to pull out.
Large eyes may force the frame away from the wall, which may be visually unappealing and may leave marks where the eyes contact the wall. Screw eyes also create stress on the sides of the frame at the point of insertion, which weakens the wood of narrow frames and can easily split dry wood. The logical replacement is the D-ring.
Framing Tips: Wire Wisdom
Picture wire threads through D-rings or the eyes of steel plates so that you can suspend the picture. Like screws, picture wire comes in different sizes (also referred to as weights), as indicated by a crosshatch (#) followed by a number. In addition, there are many types of wire, some of the more common being twisted stainless steel, plastic-coated stainless steel, multistrand braided galvanized steel, and plastic-coated copper (F). Galvanized-steel wire is the most frequently used but also the least effective. Plastic-coated stainless-steel wire won’t hurt your hands during installation, mar walls, rust, or discolor. Coated copper is softer and easier to work with but doesn’t have the strength of stainless steel.
As multistrand braided galvanized steel wire increases in diameter, the strands remain constant in size, with additional strands being added to the braid. For example, a #2 braided wire has 12 strands while a #8 braided wire has 36 strands. In contrast, all stainless steel wire contains seven strands that have been tension-twisted, like cable, and as the wire gets larger, the strands increase in diameter. This makes twisted wires (stainless steel) comparatively stronger than braided wires (galvanized steel), but also less flexible.
Determining the correct size of wire is dependent upon the type of wire you’re using. The break weight (also called break strength or break point) of braided galvanized wire should be approximately four times the weight of the frame, while the break strength of coated stainless wire should be approximately three times the weight of the frame. Hence, for a 10-lb. painting, you could use a stainless steel wire with a break weight of 30 lbs., but if you used braided galvanized wire, the break weight would have to be 40 lbs.
The table Comparative Strengths of Picture Wires (above) gives a more complete idea of the capabilities of different types of picture wire. By consulting this table you can see, for example, that a #3 braided galvanized wire is recommended for a maximum frame weight of 16 lbs., while a #3 coated stainless steel wire is recommended for a maximum frame weight of 20 lbs., even though both wires have the same break weight of 68 lbs.
The larger/heavier the wire, the more the variance between the braided (galvanized steel) and cabled (stainless steel) structures. Accordingly, #8 braided wire is rated at 36 lbs. with a 145-lb. break weight, while #8 stainless steel wire is rated at 60 lbs. with a 170-lb. break weight. Note that the softer, coated-copper wire also has a break weight of 170 lbs., but a maximum frame weight of only 40 lbs.
As an artist, you’ll most likely need wire in two or three sizes to accommodate all your picture-hanging needs. A coated stainless-steel wire probably would be your best choice, and #3 and #5 should handle most of your demands. Keep in mind that it’s better to select a wire that’s too heavy than too light.
This article on framing tips by Chris Paschke first appeared in a past issue of The Artist’s Magazine.
Learn More About Framing Your Art
There’s much more to framing and displaying your artwork than hardware, but to a large extent, the success of your presentation literally hangs on the hardware you choose. A little knowledge could save your art! For additional framing tips, read the following articles.