Can you wash the shirt?

No. The author states it is not machine-washable — nor really hand-washable. It's a one-off artistic piece, not a practical garment.

Where can I buy the parts?

The author recommends Adafruit for the LED filaments — slightly more expensive than AliExpress but convenient, and he likes supporting their open-source work. Other components (boost converters, transistor arrays, ESP32) came from his existing parts bin and sources like AliExpress.

How long did the project take?

The neon-themed event was announced less than a week in advance, so the entire design, sewing, and electronics build was completed in just a few days.

Flexible LED Neon T-Shirt — Sewable LED filaments turned into wearable neon art

A detailed project write-up by Scott Bezek documenting how he built a wearable "neon" t-shirt using flexible LED filaments (thin, ~1.8mm silicone-encased strips of hundreds of tiny LEDs, mass-produced for neo-retro Edison bulbs). Built in under a week for a company neon-themed event, the shirt features a red LED-filament llama on the back, cursive neon text with a Vegas-style border on the front, and an ESP32-driven control box with flicker/animation effects.

Key Features

Full parts list

Covers LED filaments (2x 600mm 12V warm white, 3x 300mm 3V red, 1x 1200mm 24V red), ESP32, USB battery bank, TPS61169 constant-current LED driver, boost converter, ULN2003A transistor array, black t-shirt, black thread, stiff backing fabric, tissue paper, and heat shrink tubing.

Sewing and mounting technique

Uses tissue paper templates traced from printed designs, cross-stitch (Aida) fabric as a stiff stabilizer inside the shirt, an embroidery hoop for tension, and loop stitches every few centimeters to secure the filament along the design path.

Design workflow in Inkscape

Explains how to draw a continuous path (a llama for the back, cursive text using the open Playwrite België Vlaandere font for the front), then use Inkscape's "Measure Path" feature to scale the design to fit an exact filament length — critical because LED filaments can't be cut to length.

Wiring and electronics build

Filaments are soldered to enameled magnet wire, routed through the fabric weave to ribbon cables running down the shirt, and driven by an ESP32 via a TPS61169 constant-current driver (with PWM for neon flicker emulation), a constant-voltage boost converter with series resistors for the 24V filament,

Neon-sign-style detailing

Shows how to make separate letters from a single filament run by blacking out connecting stretches with small pieces of black heat-shrink tubing (analogous to "block out" paint on real neon signs), and how to solder multiple 300mm filaments in series to reach a ~900mm path.

Enclosure

All electronics fit into a small 3D-printed enclosure with a USB-C port for the ESP32 board, battery bank power, a slot for ribbon cables with zip-tie strain relief.

How It Works

Choose and scale a design

Draw a single continuous path in Inkscape, measure it with "Measure Path", and scale it so the path length matches one of the discrete filament lengths (filaments cannot be cut without destroying them).

Transfer the template

Print the design, trace it onto tissue paper, tape the tissue to the shirt, and tape stiff cross-stitch fabric to the inside as a stabilizer.

Sew the filament down

Sew the LED filament in place with loop stitches every few centimeters along the traced line, then tear away the tissue paper (tweezers help remove it from between letters).

Wire and drive the LEDs

Solder magnet wire to each filament end, route ribbon cables down the shirt to a pocket-mounted control box, and drive each circuit from a 5V USB battery bank via the ESP32: constant-current driver for the 3V text series chain, voltage boost with series resistors for the 24V llama, and PWM-dimmed un

Pros & Cons

Pros

Complete end-to-end walkthrough with a concrete parts list, so it's directly reproducible
Covers real-world constraints and workarounds — uncuttable filament lengths, soldering filaments in series, blocking out letter gaps with heat shrink, and improvising drivers from on-hand parts
The technique is validated step by step (small test swatch before committing to the full design)
Honest about limitations, including that the shirt is not machine-washable or even hand-washable
The finished result held up well at the event and was well received by coworkers

Cons

Who It's For

Best for

Makers and hardware hobbyists who want a striking wearable LED project on a short timeline
People comfortable with basic soldering, sewing, and ESP32/PWM electronics
Anyone curious about repurposing LED filaments (sold for retro Edison bulbs) for fabric art
Cosplay and event-costume builders who need a one-off, non-washable showpiece

Not ideal for

Everyday clothing — the author explicitly notes it's not a practical garment
Anything that needs laundering, since it's neither machine- nor hand-washable

Use Cases

One-off wearable LED/neon costumes for themed events, parties, or conventions

Learning how to work with LED filaments outside their typical Edison-bulb use case

Practice projects combining soft-circuit sewing, Inkscape path design, and ESP32 PWM control

Adapting the technique to other fabric items (jackets, banners) with sewn-in glowing line art

FAQ

What are LED filaments?

Long flexible strips containing hundreds of tiny LEDs encased in a thin silicone diffuser about 1.8mm in diameter. They're mass-manufactured for neo-retro "Edison" lightbulbs, which makes them cheap and readily available for DIY projects. Adafruit sells them under the name "noods" (noodles).

Can LED filaments be cut to length?

No. One end is positive and the other negative, and they can't be shortened without completely breaking them. Designs must be scaled in software to match discrete filament lengths, or multiple filaments can be soldered in series (leaving a small non-glowing gap at each joint).

How do you attach the filament to a shirt?

Tape a tissue-paper template of the design to the shirt, tape stiff cross-stitch (Aida) fabric to the inside as a stabilizer, and sew the filament down with loop stitches every few centimeters. An embroidery hoop keeps everything evenly tensioned. The tissue paper is torn away afterward.

How is the shirt powered and controlled?

Flexible LED Neon T-Shirt