White Cap Silicone Filters (JKL Components Corp,, price TBA
Updated 11-08-06

**Because of the nature of this product, the standard review format will be foresaken.

JKL's silicone White Cap filters give you an easy, permanent and inexpensive way to change blue LEDs into any of over 80 shades of white!
The filters fit onto any 3mm (T1) or 5mm (T1 3/4) blue LED, and will work with any blue LED with a wavelength ranging from 465nm to 475nm.
Colors range from cool blue to warm white and ivory to lemon yellow! The filters are made in such a way that you can pop them onto a whole bunch of LEDs and the color will be consistent from piece to piece and from order to order (the industry calls this "repeatability").

The filters also diffuse the LED's light, giving an effective viewing angle of 180 degrees, and are designed to be stable for long-term use.

White Cap filters are very easy to use. You simply push them onto the LED's body until you hit bottom. They will never come off by themselves, but they can be removed without damaging the LED if need be.

I was provided with several different colors in the T1 size, and a single T1 3/4 filter. The colors I tried range from a cool sky blue (very neat), to pure white to a true lemon yellow! Several other shades of yellow and yellow-white were also provided, as was a CIE Chromaticity chart with the positions occupied by White Cap filters shown on it.

caps in use
White Caps installed on Nichia NSPB320BS blue LEDs.

So begs the question: Why?
Simple. In bulk quantities, blue LEDs are considerably less expensive than white ones. Using these filters on blue LEDs gives you a simple and cost-effective means of getting virtually any shade of white you may need for a particular application. Also, white LEDs generally don't match up well. That is, when you buy a bunch of white LEDs, you will find that each one is inevitably a slightly different color from the next. Using JKL's White Caps on blue LEDs gives you consistent color from piece to piece, regardless of the blue LED's original wavelength; provided it falls between 465 and 475nm.
close up of white caps caps in use
Left: Close-up of White Caps installed on LEDs.
Right: White Caps actually in use, on four blue LEDs.
Photo on right is deliberately underexposed to prevent
blooming (bright areas showing up only as white blotches).

The above photo on the left is a close-up of two LEDs fitted with White Caps.
Notice how they fit snugly, but leave just enough clearance above the LED's base flange that they can be removed without destroying the lamp or the filter.

The picture on the right shows four of the White Cap filters fitted onto four identical blue LEDs (Nichia NSPB320BS) and photographed with the LEDs illuminated. The photo was underexposed by 1.5 stops and the LEDs were driven at only about 5 milliamps.
If I used a normal iris, they would be so bright they'd all just show up as white blobs - which isn't very useful at all, isn't it? This is why they don't look that bright in the picture - but trust me, they work just fine with LEDs driven at normal current in the 20 to 30 milliamp range.

Spectrographic plot

Spectrographic plot

Spectrographic plot

Spectrographic plot

Spectrographic plot
Spectrometer plots of these filters over blue LEDs.
Ocean Optics USB2000 Spectrometer on loan from TWO-CUBED.

Testing of this product depended on the availability of 3mm blue LEDs, which I was not able to locate until just recently. Now that I have hundreds of them, I can finish what I started.

Update 10-14-00 and 11-03-00:
I have found T1 blue LEDs from two different manufacturers, so this show can finally get on the road, including the addition of photographs.

Update 11-04-00:
Filters will work on any blue LED within the specified wavelength range, but best results are obtained when used with Nichia NSPB320BS, an LED with a wide 45 viewing angle. When used with these wide-angle LEDs, the light is very even and consistent on the surface of the treated LED, and as a result, on the surface of whatever you are illuminating with them.

Several visitors have likened White Cap filters to "condoms for LEDs"; and it is easy to see why.
So if anybody submits an order for "a dozen 39-02-W02 LED Condoms" you have nobody to blame but yourselves. Take it with a light heart, and fill the order. :)

They really do work
Permanent, but removeable if need be
Diffuses LED light into a wide, even field suitable for backlighting switches and small silkscreened panel graphics
They're nontoxic when swallowed, and flushable too. (but please don't - they're too good for that!)

The fact you actually have to take the time to install them onto each individual LED. For an installation with hundreds of LEDs, this could add to assembly time
They do cut down on the LED's overall brightness, but this is to be expected of any optical filtering method of a light source.

JKL 'White Cap' Silicone LED Filters * WWW.JKLLAMPS.COM

Do you manufacture or sell an LED flashlight, task light, utility light, or module of some kind? Want to see it tested by a real person, under real working conditions? Do you then want to see how your light did? If you have a sample available for this type of real-world, real-time testing, please contact me at

Please visit this web page for contact information.

Unsolicited flashlights appearing in the mail are welcome, and it will automatically be assumed that you sent it in order to have it tested and evaluated for this site.
Be sure to include contact info or your company website's URL so visitors here will know where to purchase your product.

WHITE 5500-6500K InGaN+phosphor 
ULTRAVIOLET 370-390nm GaN 
BLUE 430nm GaN+SiC
BLUE 450 and 473nm InGaN
BLUE Silicon Carbide
TURQUOISE 495-505nm InGaN
GREEN 525nm InGaN 
YELLOW-GREEN 555-575mn GaAsP & related
YELLOW 585-595nm
AMBER 595-605nm
ORANGE 605-620nm
ORANGISH-RED 620-635nm
RED 640-700nm
INFRARED 700-1300nm
True RGB Full Color LED
Spider (Pirrahna) LEDs
True violet (400-418nm) LEDs
Agilent Barracuda & Prometheus LEDs
Oddball & Miscellaneous LEDs
Programmable RGB LED modules / fixtures
Where to buy these LEDs 
Links to other LED-related websites
The World's First Virtual LED Museum
The Punishment Zone - Where Flashlights Go to Die
Legal horse puckey, etc.
LEDSaurus (on-site LED Mini Mart)

This page is a frame from a website.
If you arrived on this page through an outside link,you can get the "full meal deal" by clicking here.