This article, from the manufacturer's point of view, summarizes common product quality problems in the market, and hopefully will help buyers who need to identify products.

Q1 : What materials are currently used in eyelash products?

There are synthetic fibers, mink hair, human hair and other animal hairs.Some animal hairs are uncomfortable to wear and can even cause eye irritation, so honest companies are eliminating their use.
Mink hair is used in eyelashes which is soft and non-irritating, so prices and profits are higher.In order to make huge profits, some manufacturers choose to use sea mouse hair as mink hair, or even synthetic fibers as mink hair.So that they can make more profit with lower material costs.

Q2: How to tell the difference between mink lashes and synthetic lashes?

Here is an introduction of distinguishing between synthetic lashes and mink lashes —— Burning.
When igniting mink hair lashes and synthetic lashes simultaneously, the fibre hair will burn rapidly into charred black, which is hard when cooled.There will be a pungent plastic smell in the process.
Mink fur burns more evenly and can turn into black particles after burning, which can be gently whisked into powder , with the burning smell of human hair which is not irritating.If you can't tell the difference, check out this video :

Contrast from the appearance and sense of touch ---- high-end mink hair will have a good stiffness and is soft at the same time. On closer inspection, it  also have a good hair glossiness, be washable without deformation and have self-cleaning ability. Other animal hair, however,is rough tips ,lustreless and hard, and will basically be eliminated after one or two wears.