At Lii Lash, our commitment to excellence begins with one crucial foundation: quality control. Every black eyelash extension tray we produce goes through six meticulous production steps, each paired with its own strict QC checkpoint.

But what truly sets our process apart isn’t just the structure — it’s the people behind each step. Each QC stage is managed by a seasoned expert whose skill and experience ensure that every lash meets our uncompromising standards. 

In this blog, we take you behind the scenes of two essential early stages — Raw Material and Line Processing — to introduce the person responsible for upholding our precision from the start: our Line Department Manager. Let’s explore how true quality begins, long before the lashes reach the tray.

How It All Begins: Raw Material & Line Processing in Lash Production

Raw Material Stage

Every premium lash begins with exceptional raw materials. At Lii Lash, that means sourcing only high-grade PBT fibers from trusted suppliers in Germany, Japan, and Korea. Whether mink-style, silk, matte, or semi-matte lashes, each type demands a specific fiber to deliver the ideal look and feel.

Before production begins, all fibers are rigorously inspected, classified, and sealed in transparent containers to guard against moisture and contaminants. This critical step protects our fibers’ purity and ensures each lash performs to the highest standard—from start to finish.

Line Processing Stage

Once the lashes pass inspection, they move on to the molding stage—a crucial step for creating flawless consistency. Here, lashes are meticulously arranged onto custom-designed molds, ensuring even spacing, balanced shape, and uniform density. This process guarantees that every lash strip has a consistent layout, is free from irregular lengths, and has just the right amount of fullness.

Next, specialized adhesive tapes anchor the lashes in place, and a precision hammer precisely trims them to remove any stray or excess fibers. Since lash styles differ in thickness and length, each one requires a specific type of tape. That’s why our craftsmen must have both technical expertise and refined judgment—selecting the ideal tape not just for the lash type but also to match the application preferences of professional lash artists.

Early-Stage Lash QC: Procedures and the Leader Who Oversees Them

Meet Mrs. Thu, Line Department Manager at Lii Factory

When Manufacturing Precision at Lii Hinges on One Key Person.

The opening steps of lash production are complex—yet tightly controlled. At the heart of this precision is a dedicated expert who oversees it all. Now we’re excited to introduce the person who ensures the smooth operation of these critical first stages: Mrs.Thu, Lii’s Line Department Manager.

At the forefront of Lii’s production journey are the Raw Material and Line Processing stages—both handled by our largest department, led with expertise and dedication by Ms. Thu.

During the two meticulous production stages and their accompanying rigorous quality control checkpoints, Mrs. Thu applies both her extensive professional expertise and strong leadership skills to ensure the flawless quality of every Lii Lash product. It’s no coincidence she’s been entrusted with such a critical responsibility.

With a background in freelance business and years of collaboration with our team, Mrs. Thu has demonstrated exceptional attention to detail and a meticulous approach—both of which are essential in the crafting of a product as small, complex, and precision-driven as eyelash extensions. At Lii, we prioritize quality over speed, which means each handmade lash tray takes longer to produce than the industry standard—and we hold ourselves to even higher precision benchmarks.

But quality oversight is just one part of her role. As the manager of our largest production department, Mrs. Thu not only oversees the technical excellence of semi-finished products but also navigates the complexities of human management. Leading a team where precision, technical skill, and teamwork must come together seamlessly requires not only expertise but also a deep understanding of how to bring out the best in people—something Mrs. Thu exemplifies every day.

How Mrs. Thu Leads and Executes These Precise QC Steps

QC Oversight: Raw Material Stage

Although our raw materials are pre-screened before arrival, they undergo a second, thorough inspection during the preparation phase. This step ensures consistency in material quality, accurate thickness, and proper lash tapering—all essential to achieving our high standards.

So how does the Line Department Manager contribute to this process? Despite her managerial role, Mrs. Thu personally inspects each roll of PBT fiber at the start of every day, one by one. Her hands-on approach ensures that only flawless materials enter the production line.

Once the fibers pass her initial check, the craftsmen take over at the worktable. Using specialized tools such as lash thickness gauges and skein length gauges, they carefully verify the dimensions of each skein. If any roll fails to meet the exact specifications, it is immediately removed from production—ensuring that every tray begins with precision from the very first strand.

QC Oversight: Line Processing Stage

Ever wondered how Lii Lash achieves such consistently dense and uniform lash strips? The answer lies in Mrs. Thu’s leadership and deep expertise, especially during the line processing stage—a critical phase that separates an ordinary lash tray from a premium one.

Unlike conventional methods where lashes are simply laid onto a mold and taped, our craftsmen carefully spread each fiber to eliminate gaps—even under close inspection and direct lighting. This meticulous approach ensures maximum fullness and consistency in every tray. At Lii, 13000 lashes per tray is a must, allowing lash artists to serve more clients and reduce the cost per application. We don’t just aim for volume—we focus on achieving the perfect balance of density and uniformity that defines the Lii Lash standard.

Throughout production, Mrs. Thu actively supervises the process, frequently checking workstations to ensure this high-density benchmark is met with minimal margin for error. Her hands-on involvement guarantees that each lash strip not only looks perfect but also performs flawlessly in the hands of lash professionals.

Here’s another behind-the-scenes secret: Lii Lash’s Line Department produces up to 15,000 lashes every single day—all before they even reach the heat-curing stage. It’s an impressive volume for a product that demands such precision, and while it may sound intense, this is the daily rhythm our Line Department maintains.

Under Mrs. Thu’s leadership, this production target is met consistently, thanks to her sharp oversight and deep commitment to both quality and efficiency. She ensures that every lash is crafted to our exacting standards, without compromise—even at scale.

More Than Lashes — It’s a Human Story

At Lii Lash, we’re known for crafting premium eyelash extensions — but lashes aren’t our only focus. At the heart of our success lies something even more important: people.

Across every department, role, and rank, it’s the dedication and craftsmanship of individuals that shape who we are. Behind the flawless trays and precise quality checks are human stories — stories of care, passion, and quiet excellence.

Through this blog, we proudly shine a light on Mrs. Thu, whose leadership and unwavering attention to detail help define Lii Lash’s industry-leading standards. Her journey reminds us that true quality begins with people — and thrives through purpose.