Acrylic diffuser material recommendations?

Hey there folks! I want to build some custom light bars using acrylic as the diffuser material. Does anyone have any recommendations for a company that has good options? I’ve tried diffusion specific led acrylic from Tap before, but either it was too thin, or my distance wasn’t far enough from the leds to really blend the hot spots.

I don’t need total removal of hot spots, but something that makes it a bit more smooth. Assume a max of about 1 inch from the led to the outer edge of the acrylic for space.

i’m using the led diffusion acrylic from TAP plastics in the backfire sign i created last year.

the distance i settled on from the LEDs to the acrylic was 27mm before i found the optimal distance to blend all the lights and not have hot spots.

BUT - also keep in mind that hot spots are dependent on a couple factors. the distance between each LED, the point brightness of each LED, and lastly, the distance between LED and the diffuser material.

the smaller LEDs you have and the closer they are together, the less of a distance you’ll need between the lights and the diffuser materials and the more easily it will blend.

just an example - instead of running a 30 led /meter 5050 strip, using a 90 led/meter 2020 strip would be far easier to diffuse.

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another thought - if you’re not able to switch to a higher density strip, you could take steps to try to minimize any light absorption in between each led, such as applying a white film or reflective material with cutouts for each LED over the strip so that you get the most reflectivity… this is just me spitballing and i have not tested any of this and do not know how effective this would be.

Dear Alex, as a general rule i maintain as min. distance between led and diffuser the spacing between leds. For strips of 60 leds/m this would be 17mm. Now if you like colors, (everyone who likes Pixelblaze likes colors, i guess) and you want the colors to blend in with each other, this distance could be anything between 20 and 40mm. PMMA or acrylic is a good diffuser, i always use the sanded (or iced) version. Also exist in tubes of varying diameter.

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Thanks for the rule of thumb, I’ll play around with it :slight_smile:

Finally got my 3d printer going and can test different materials for diffusion as a stop gap, and then will pick up some acrylic to play with as well!

for 3D prints, with organic flowing shapes, i’ve printed with transparent PETG with extra thick perimeters (3-4 layers instead of the usual 2), light infill

experiment with infill shapes since they do show through… gyroid and hexagon patterns are especially good in my opinion.

then sand down the external shell with sandpaper, working down to a very fine grit wet sandpaper and you’ll get pretty good outcomes!

One example of transparent PETG with gyroid infill


Timster has great tips here about the relationship between density, distance, and brightness.

Selecting an acrylic with lower light transmission will generally blend things more for you. Thickness, textured matte surface finish, or more white additives per unit of volume are all ways to reduce transmission and increase diffusion angle.

You can see some of this relationship in the Plaskolite lighting solutions product sheet. This manufacturer makes the acrylic and polycarb used in many commercial fixtures. You can request a chip sample pack from their website. For a polycarb project, I really liked DX-NR and LW3.

Have you tried Tap’s 45% transmission “Lighting white” in 1/4" thick? I think that would blend 60/m 5050s pretty well at about an inch offset.

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