Learn About Blow Molds - FAQs

Helpful Information about Blow Molds - Lighting

Blow Mold Lighting – Kelvin (K), Lumens, & Watts:    Watts is what most folks are familiar with for the strength or brightness of a light bulb. With LED bulbs, the more important numbers for brightness are now the Lumens and the Kelvin.  Let’s dive in:

Kelvin (K):  This is the frequency of the light. This can contribute to the brightness effect, although more along the lines of the warm or cool appearance of the light.  The lower the Kelvin, the softer and warmer the color temperature will be.  The higher the Kelvin, the cooler white the light will be.  Folks often like to have higher Kelvin bulbs in their predominantly white blow molds, and lower kelvin bulbs in the blow molds with color. 

Lumens:  This is the measurement of light output. It is like saying how strong the light source is. The higher the Lumens number, the brighter the light bulb will be.

Watts:  This is how much power is consumed by the bulb.  We used to equate Watts with brightness (Lumens) back in the good ole days of incandescent lights; because the more power the bulb used, the brighter it would typically shine.  Forgetting about the horrid years of when CFL spirals of toxic dullness were foisted upon us, we now have LED lights which are much more efficient and a 9-watt LED bulb is almost always much brighter than a 40-watt incandescent light.  As a result, Watts are still necessary for those doing the math on how many bulbs you can put on one circuit, but not nearly as informative as Lumens and Kelvin when picking out the “right bulb” for your display.

Equivalent Watts:  This is when LED bulbs mention the overall strength and output replicated by a similar incandescent bulb.  When an LED Bulb says it is 9 watts but 60-watt equivalent, it is the simplest way of saying you would see a similar strength light output from this 9 Watt LED as you would have from a traditional 60 Watt Incandescent.  With an LED though, you use much less power.

Dimmable:  With modern Christmas and other Holiday displays that use programmed switching and other types of light control, or for indoor settings such as dining rooms or areas with dimmer switches, dimmable bulbs are recommended.  When a dimmer is engaged, it alters the way the power is delivered to the light bulb. Non-Dimmable bulbs don’t know how to handle that and simply fail to work.  Dimmable bulbs are built to handle the variation and will change their intensity based on the dimmer settings. 

Incandescent:  Classic light bulbs that generally use 10x the energy vs the light they actually produce.  Can generate significant heat and may require additional electrical circuits for displays of more than a few bulbs.  Last only a few hundred to 1500 hours of use, fragile if dropped or mishandled.

LED:  Newer light bulbs using modern technology to deliver more light using far less energy. Generates far less heat for the same light output vs incandescent bulbs, last much longer (10x – 40x longer) and typically not near as fragile or breakable.

E26 / Medium or Standard Base / A19 & A21: “Regular” light bulbs in the USA use the socket size of E26.  These are also called Medium or Standard Base light bulbs.  You may also see sizes of A19 or A21.  These don’t refer to the socket itself, but to the shape of the bulb.  For many years, A21 bulbs were the most common incandescent bulbs.  Many LEDs are closer to A19 bulbs.  Unless they’re side by side, it can be difficult to tell which is which.  The most important piece of this is when you’re working with General Foam (GFP) flared light sockets, you will want to test fit the bulb and ensure it screws in far enough to light up.  Squatty bulbs, which include some brands of newer LEDs like those made by FEIT the last couple years, won’t go in far enough.

E12 / Candelabra / C7:  Smaller bulbs common in Blow Molds use the E12 or Candelabra size base. They’re commonly referred to as C7 bulbs, and that has to do with their shape and their diameter being 7/8” (the “7” in “C7” is how many 8ths).   What is important about these bulbs is often the blow mold isn’t very large or deep, so while a taller and brighter candelabra bulb may fit, it may be dangerous, especially if you’re using an incandescent bulb.  Taller bulbs may generate enough heat to melt part of the blow mold. Additionally, higher wattage incandescent candelabra bulbs may draw more wattage than your cord is rated to handle.  Using newer and stronger LED bulbs will produce solid amounts of light without those same heat or wattage risks presented by classic incandescent bulbs.


What bulbs are right for my blow molds? – There are many different opinions on what kind of bulb to use in what blow mold.  As long as you’re starting with the correct size bulb for the socket and you’re not exceeding the capacity of your cord and circuit, you mostly get to choose your bulb based on your taste and preference. 

I’ve found that high Kelvin / cool white bulbs work great in snowmen, polar bears, and other mostly white blow molds.  I enjoy low Kelvin / warm white bulbs in blow molds with some color.  I also make sure to use a lower Lumens bulb in white blow molds so they don’t wash out the rest of the display. Often a 7-watt LED (typically 25-watt equivalent, 200-250 lumens) bulb will work well in a smaller white polar bear or snowman, where I might need 800 lumens to light up those large, darker nativity camels.  The bigger the blow mold, the more Lumens I’m typically looking for. 

For the smaller sockets/bulbs, I’m almost always going with the upgraded 1.5-watt 130 lumen C7 size bulb as I want the most I can get out of those typically undersized fixtures. 

The prices of bulbs keep coming down, so it is getting more feasible to try out different Kelvin (color temperature) and Lumens (output) to see what works best for you.