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C7 & C9 Bulbs

LED C9 and C7 bulbs are a central element in most Christmas Light Installations. There are several factors to consider when planning how to use C7 and C9 Bulbs in your display including placement and spacing as well as bulb color and finish. This guide is designed to help you navigate all of the choices and select the perfect style of C7 ir C9 bulb for your display.

The difference between C7 and C9

A great starting place is to understand the the difference between the two bulb styles. C9s Bulbs are larger and have a wider base diameter than C7 Bulbs. LED C9s are most commonly installed because their large size makes them brighter and more visually appealing when viewed from a distance.


C9 bulbs use an E17 (Intermediate) base and C7 bulbs use the E12 (Candelabra) base. Both bulb styles are typically installed on pre-socketed wire with even spacing between each bulb. Individual sockets can also be used for accent items like cascades (meteor tubes) and new dripping icicles as well as LED Filament accent bulbs to add a decorative touch to your display.

Evergreen Holiday Lighting offers a wide range of socket and bulb types that are perfect for any application including linear projects like lighting rooflines, fences, and outlining pathways as well as free-form projects like tree canopies!

C9 vs. C7 Size Comparison

Placement and Spacing

These two elements of the design tend to go hand-in-hand. Depending on your architecture and the look you would like to achieve, presocketed wire is available with assorted spacing options ranging from 6" - 24" between sockets. The most popular option is C9s spaced every 12" along the wire.


  • 12" Spacing is popular for consistent brightness without appearing too busy.

  • 18" Spacing is useful for climbing peaks on longer Spanish tiles.

  • 24" Spacing is effective for tree canopies (especially in combination with mini lights) and can be used for festoon-style swags

  • 6" spacing is perfect for displays with a repeating color pattern as the sequences repeat more often

The most common place to we install C9 bulbs is along rooflines. When lighting a roofline, we consider two main areas - the Facia or front of the roof  to define the shape followed by the Peaks and Ridges to outline the remainder of your roof. Depending on the material and position on the roof we offer an assortment of attachment options.


The installation above uses Warm White Faceted C9 Bulbs with the popular 12" spacing between sockets

Garden Outlines

C9 Bulbs on bed stakes up to 12" tall to are effective to accent walkways, planters, edgings and more! Lighting at ground level is an excellent way to finish your display because it provides context to the rest of the light and anchors the scene in to the yard, tying the display together.



C9s can easily be attached to fences and walls to accent features around your property or community entrance.

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Sign Monuments

Another common use of C9s is to accent sign monuments at the entrance to a neighborhood. This can be done with as a stand alone look or combined with large bows, garland, or wreaths for a distinct holiday look.

Bulb Color and Finish

Now that you have an idea of where we will install the lights and what the spacing might look like, the next choice with C9 bulbs is the bulb itself! LED C9 and C7 Bulbs are commonly sold in three styles:

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All three finish options are available in C9 and C7 sizes with different color selections depending on finish choice. Each style has it strengths as mentioned below.


This is the most common type of LED C9 and is the style you see on most professional installations across the country. The faceted lens allows light from a point source diode to spread over a large area for maximum effect. The facets on the lens add a starburst dispersion pattern to the light source that causes the light to shimmer as your perspective changes to the bulb.


Many Christmas Installations use these faceted bulbs in Warm White, however Cool White is also a common choice. Faceted bulbs are available in a wide range of colors.

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The opaque bulbs are not as common in installations, however some people prefer the opaque design as it most closely resembles the classic C9 look. The diffusion provided by the opaque lens on this style of bulb make these a great choice for people who feel that modern LED Christmas Lights are too intense.


This transparent style of bulb is the newest to the market and is a direct result in advances in LED Technology. These premium bulbs come in a shaterproof casing and have a strip of tiny colored LEDs inside that resemble the filament of an incandescent bulb. These are perfect for installations where the viewers will be closer to the bulbs and able to appreciate their unique style and they also provide a fun retro look to rooflines.


Have a Design in Mind?

Whether you know exactly what you want or still need some assistance, Evergreen Holiday Lighting is here to help! Our experienced design team is standing by to turn your display into a reality.  Book a Free Design Consultation Today!

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