One key component in a channel letter is the return. The return is the letter’s metal side structure, as shown in Diagram 1, below.
Returns are available in differing depths ranging from two to eight inches, with five inches being the most common. However, three-inch letter returns are becoming more popular and have several potential uses and benefits. This article briefly reviews some of the considerations involved with using three inch returns on channel letter signage.
What Are the Purposes of a Letter Return?
A channel letter return has several purposes. First, it creates the actual enclosed “channel” from which this signage type is named. In addition, the return also provides the physical protrusion of a letter set. This projection provides channel letters with an additional level of visibility lacked by flat signage.
Third, the return both provides the LED mounting area and encloses the light chamber that focuses the illumination on the letter face (or back if the channel letters are reverse lit.) So the return is an important multi-purpose letter component.
Channel Letter Illumination
One initial consideration with the use of a three-inch return is the illumination requirements. Successful illumination of a letter face on a three-inch return requires a different LED viewing angle than does a five-inch return.
Diagram 2, below, illustrates the same LED viewing angle used in both a five-inch and a three-inch return—note the difference. The three-inch return does not provide as broad an illumination area, so a higher LED viewing angle may be needed. A viewing angle that is too narrow may result in “hot spots.”
Matching Component Projection
A second consideration regarding three-inch returns is their ability to ensure all components of a given sign structure have an equal projection from the building façade.
For example, a channel letter set may have one separate component (such as a logo box) that has an eight-inch protrusion. But suppose a second component of that same sign structure is a raceway mounted channel letter set.
The raceway alone has a five-inch depth, so if the overall sign structural projection (8”) is to match the logo box projection it must protrude only three more inches from the wall. Using a standard five-inch return would mean these two sign elements would have differing mismatched protrusions (which has an unprofessional appearance.) Specifying a three-inch letter return may solve that issue.
Channel Letter Design
The physical letter design is another consideration in your selection of a channel letter return depth. If your customer’s design calls for a serif font that has tight channel areas (or is an “artistic” font with curved letters), keep in mind that such an arrangement opens up the possibility of non-optimal letter illumination when using five-inch returns. That is because LED module installation and placement is more difficult as the return channel becomes smaller (as it sometimes does in serif or “artistic” font designs.)
Specifying a three-inch return can be helpful. This return depth poses less of an impediment to LED module installation even in tight letter areas. Corners and crevices inside a return are more easily reached when an installer has only a three-inch return to work around.
Ease of Service
An additional consideration for three-inch returns is the potential ease of field service. Signage service on a mounted letter set with three-inch returns will typically be simpler than is servicing the same set with five-inch returns.
Just as it was with the initial LED installation, the letter set interior channels are more accessible. So easier channel letter service (and potentially lower service call costs) can be another benefit of using three-inch returns.
Open Face Channel Letters
Open face channel letter sets offer another potential use of three-inch letter returns. Though the usage of neon illumination has decreased, neon-illuminated open face sets are still periodically specified. For that letter type, a three-inch return will result in a more effective letter set due to more exposure of the actual neon tubes.
Return Color Selection
Color availability is another potential concern with three-inch returns. Three inch is a less commonly specified return depth, so many letter producers do not stock the same selection of colors (this does not mean that a given pre-painted color is not available in three inch. It only means that a channel letter producer is less likely to carry an ongoing inventory of that specific color.)
For example, at Direct Sign Wholesale the standard three-inch return colors currently stocked are:
That is a far smaller assortment than is typically inventoried for five-inch letter returns. “However, if a customer places a large order of letters (50 sets or more) with three-inch returns with a non-standard color, we can order five-inch coil and have it trimmed,” says DSW production manager Chris Rogers.
For smaller channel letter projects, however, it may be more economical to paint the three-inch return instead of ordering that specific color from the coil manufacturer. Either option will mean an additional cost to your customer, but painting may be less expensive choice than ordering a pre-painted custom three inch return color.
Minimum Letter Specifications
Another variable that may be impacted by the return specification is the minimum letter size (or the “minimum spec”—the smallest vertical letter size a producer is willing to fabricate.) For instance, at Direct Sign Wholesale the minimum letter height is eight inches.
However, a three-inch return specification may change the minimum permissible letter specification to a smaller vertical amount. So if your customer is requesting an unusually small channel letter size, specifying three-inch letter returns may assist in meeting their project requirement.
Letter Set Weight
Letter set weight is another consideration with the three-inch return depth. A substantial part of a channel letter set’s bulk comes from the weight of the returns. Removing two inches from that component reduces the letter set weight.
This can be helpful when the installation of a three-inch return letter set is planned. A lighter letter set means an easier sign placement and positioning on the wall. It may also mean that a one-person installation is possible instead of using two people.
This weight difference also may mean a shipping cost decrease (assuming the carrier partially bases their charge on weight.)
Permitting is another consideration when the depth of the channel letter return is specified. As mentioned before, a shallower return reduces the protrusion from the building facade. Some cities have a maximum permissible sign projection distance. Five-inch returns may cause your customer’s sign to project further than is allowed under city permitting law (particularly when the letters are raceway mounted).
So the return specification has multiple considerations for the successful completion and installation of a channel letter project. The usage of a three-inch return may allow you to meet permitting requirements, specify smaller letter sizes from the manufacturer and make easier field service calls.