Retrobright

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Process for removing yellowing from ABS plastic

title: "Retrobright" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["cleaning-products", "plastics", "hacker-culture"] description: "Process for removing yellowing from ABS plastic" topic_path: "general/cleaning-products" source: "https://en.wikipedia.org/wiki/Retrobright" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary Process for removing yellowing from ABS plastic ::

thumb|A [[TRS-80 Color Computer]] showing significant yellowing thumb|The same computer after treatment, showing yellowing largely reversed

Retrobright (stylized as retr0bright or Retrobrite) is a hydrogen peroxide-based process for removing yellowing from ABS plastics.

Yellowing in ABS plastic occurs when it is exposed to UV light or excessive heat, which causes photo-oxidation of polymers that breaks polymer chains and causes the plastic to yellow and become brittle.

History

One method of reversing the yellowed discoloration was first discovered in 2007 in a German retrocomputing forum, before spreading to an English blog where it was further detailed. The process has been continually refined since.

Composition

Retrobright consists of hydrogen peroxide, a small amount of the "active oxygen" laundry booster TAED as a catalyst, and a source of UV.

The optimum mixture and conditions for reversing yellowing of plastics:

  • A hydrogen peroxide solution. Hydrogen peroxide-based hair bleaching creams available at beauty supply stores can also be used, and are viscous, allowing them to be applied with less waste (especially to large pieces such as computer panels or monitors). The cream must be carefully applied and wrapped evenly with plastic wrap to avoid streaks in the final product.
  • Approximately 1 ml per 3 liters (1 part in 3000 by volume, alternatively teaspoonful per US gallon) of tetraacetylethylenediamine (TAED)-based laundry booster (concentrations of TAED vary).
  • A source of ultraviolet light, from sunlight or a UV lamp.

Xanthan gum or arrowroot can be added to the solution, creating an easier-to-apply gel.

Alternatives

Sodium percarbonate may also be used by dissolving it in water and following the usual steps for hydrogen peroxide, as it is sodium carbonate and hydrogen peroxide in a crystalline form.

Ozone gas can also be used for retrobrighting, as long as an ozone generator, a suitable container of sufficient size and a source of UV are available, but can take longer than other methods.

A simpler but slower process involving merely exposure of the yellowed plastic to bright sunlight has been described, variously called 'Sunbrighting' or 'Lightbrighting'. This has both empirical evidence of effectiveness and the theoretical backing of some published scientific literature, which emphasises exposure to strong visible light while minimising ultraviolet exposure.

Effectiveness

The long-term effectiveness of these techniques is unclear. Some have discovered the yellowing reappears, and there are concerns that the process weakens and only bleaches the already damaged plastic.

Similar processes

The usage has also expanded to other retro restoration applications, such as classic and collectible sneaker restoration.

References

References

  1. Ángel Jiménez de Luis. (May 25, 2010). "Retr0bright lava más blanco".
  2. (August 23, 2013). "Photodegradation and photostabilization of polymers, especially polystyrene: review". SpringerPlus.
  3. (February 19, 2007). "Forum64 — Restaurierung eines C-64G, oder das Gastgeschenk des DOC64".
  4. (July 28, 2010). "The "Retr0bright" Project".
  5. Doctorow, Cory. (March 2, 2009). "Open source computer polish: Retr0Brite".
  6. Mossesgeld, Rico. (July 28, 2010). "How To Restore Your Beige Retro Hardware". [[Tom's Hardware]].
  7. Maushammer, John. (March 2, 2009). "Un-Yellow Old Plastics – Retr0brite!".
  8. Murray, David. (20 August 2017). "Adventures in Retrobrite - New techniques for restoring yellowed plastic!".
  9. Narcisse, Evan. (September 24, 2014). "The Secret To Keeping Old Consoles Looking New? Hair Product.".
  10. Murray, David. (April 6, 2013). "How to fix yellowed plastics on old computers!".
  11. (May 27, 2018). "How Retrobright Works! - The Geek Pub". The Geek Pub.
  12. Stewart, Terry. (January 17, 2013). "Retr0Bright (or RetroBright) treated plastics re-yellowing even with minimal light exposure?".
  13. Petersen, Anja Liss. (January 19, 2011). "Afrensning af plast med RetrObright".
  14. Flood, David. (April 14, 2018). "A Look into the Yellowing and Deyellowing of ABS Plastics".
  15. "How to Easily Restore Yellowed Shoes".

::callout[type=info title="Wikipedia Source"] This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page. ::

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