What is it?

This listing is for 25 square feet of industrial grade Dry Etching Photoresist film. Each roll is 25 feet long by 12” wide. This is top-quality industrial grade dry etch film in hobbyist quantities. Brand Name is: Eternal Technology. Specific type is: Eternal Laminar 9220 Material is extremely uniform and reliable, unlike the ugly, splotchy “blue stuff” that comes from mainland China and is totally frustrating to work with. This film is made in the USA, by one of the largest producers in the world, and compares directly to the quality and behavior of Dupont Riston films.

Why did you make it?

High quality photo resist film for DIY PCB etching is very hard to obtain except in 250ft rolls, which puts the pricing and quantity outside of most hobbyist's reach. The alternative is small quantities of splotchy and terribly uneven film that has flooded the market from Asia, but is almost impossible to use successfully, due to that knockoff material's poor uniformity. My product is top-grade film in reasonable DIY quantities intended to give access to professional-quality materials to Makers who are interested in PCB etching or other types of photo-fabrication.

What makes it special?

Excellent Quality, Reasonable Quantities, Great Price, Low Curl, Careful Shipping and Handling Features quick exposure times (5-60 seconds) using 350-400nm UV light. Works well with UV LED lamps, inexpensive black light fluorescent bulbs, or traditional mercury vapor systems. Non-toxic water-based chemistry. For best results apply this film to FR4 laminate using a hot laminator such as a Scotch pouch laminator on the thickest (5 mil) setting. Develops in 1% soda ash (sodium carbonate, also known as washing soda) solution after exposure. Exposed film strips off with a 1% sodium hydroxide solution or 10% soda ash once etching is complete. Spray oven cleaner (the type with lye) is also an effective stripper for this resist once etching is completed. Gives excellent results with a variety of common acidic etchants, Ferric Chloride, Cupric Chloride, Sodium Persulfate, Ammonium Persulfate, etc. Excellent tenting properties for bridging drilled holes. Film is fresh: Expiration date September 2026. Product ships on large-diameter rigid PCV core with protective end-plates suitable for smooth unspooling. 2” diameter core reduces rollup after cutting to size. Rolls are protected from exposure to ambient light with two layers of 6mil heavy-duty blackout bags.

Suggested use-cases: -DIY PCB fabrication for electronic circuit boards. -Metal plate etching for plaques and awards -Small-scale intaglio art printing