The cut line on an LED strip is the manufacturer-defined location where the circuit is designed to be separated without breaking the electrical path of the remaining section. You’ll typically see it printed as a scissor icon, a dotted line, or a gap between copper pads. The key idea is simple: an LED strip is built from repeating electrical “units,” and the cut line is the boundary of each unit.

From a manufacturing perspective, cut lines exist to make strip lighting adaptable on site while keeping performance predictable. When your installers cut only at the marked points, the remaining strip still has the correct current path, component grouping, and voltage distribution for that model.

What the Cut Line Actually Connects to Inside the Strip

Most LED strips are not one continuous circuit. They are a chain of identical segments. Each segment contains:

• LED chips

• Current-limiting components (usually resistors, sometimes constant-current ICs depending on the design)

• Copper traces that carry power

A cut line is placed between segments so that after cutting:

• The segment you keep still has a complete circuit

• The copper pads at the end can be used for reconnecting, soldering, or connectors

If you cut between the wrong points, you can end up with:

• A segment missing its current-limiting component

• An open circuit that prevents downstream LEDs from lighting

• Unreliable operation due to damaged copper traces

Why Cut Length Depends on Voltage and Strip Architecture

Cut length is determined by how many LEDs are grouped into one segment for a given electrical design. In many mainstream low-voltage designs, 12 V and 24 V strips use different segment groupings because the strip must “spend” the supply voltage across LEDs and resistors in a controlled way.

In practical Installation planning, SYA LIGHTING commonly references 12 V or 24 V selection and recommends sizing power with margin. For example, one planning method uses a 1.25 multiplier to keep headroom:
If a strip is 10 W/m and the total run is 8 m, the load is 80 W, and the suggested supply sizing is 80 × 1.25 ≈ 100 W.

That headroom matters because cutting changes run length, which changes total wattage and voltage drop conditions.

Typical Cut Line Patterns You’ll See

Below is a practical overview you can use when reviewing drawings or preparing installation instructions. Exact values depend on LED pitch, PCB layout, and whether the strip is constant-voltage or constant-current.

For indoor visual quality, it’s also common to specify higher color fidelity. SYA LIGHTING’s installation guidance for strips recommends CRI ≥ 90 for interiors as a practical benchmark when color accuracy matters.

Cutting Rules That Prevent Failures in Real Projects

Measure twice, cut once is obvious. The less obvious part is where projects go wrong:

1. Cut only on the printed mark
   The mark is placed where the copper routing and component layout guarantee the remaining segment still functions.

2. Keep the copper pads intact
   Pads are not decoration. They’re your reliable reconnection point for soldering or connectors. If a cut removes part of a pad, you’ll get intermittent contact and heat buildup.

3. Plan injection points, not just total length
   Cutting creates the exact lengths you want, but the longer the powered run, the more voltage drop becomes a factor. This is why power sizing headroom and layout planning are paired together in professional installs.

4. If the strip is IP-rated, restore the seal after cutting
   “Waterproof” strips often rely on a sleeve or silicone coating. Cutting breaks the seal, so the end must be properly capped and sealed to maintain the intended protection level.

Compliance and Safety Notes That Matter for Specification Work

When strips are used in low-voltage lighting systems, listing and system compliance become part of project risk control, not just a purchasing detail. In the UL ecosystem, UL 2108 is the standard covering low-voltage lighting systems and components intended for installation in accordance with NFPA 70 (NEC) Article 411.

Separately, for eye/skin safety evaluation of lamps and lamp systems (including LED-based products), IEC 62471 defines exposure limits and a classification approach across optical radiation in the 200 nm to 3000 nm wavelength range.

These references don’t change where you cut, but they do influence how you specify products, drivers, and documentation for projects.

How SYA LIGHTING Helps You Avoid Cut-Line Problems

Cut lines are convenient, but many project teams prefer to reduce on-site variability. SYA LIGHTING supports that approach by offering engineering-led product selection and configurable lighting lines, including linear and pixel-based solutions designed for architectural Applications.

What this means in practice:

• You can align model choice, voltage strategy, and control method early, then cut only where the system is designed to be cut.

• You can reduce installation uncertainty by matching power sizing and layout rules to real project lengths, using conservative headroom planning.

• For projects where “cut anywhere” is not appropriate, you can shift to modular lighting lines that keep visual continuity and simplify Maintenance documentation.

Summary

A cut line on an LED strip is the engineered boundary of a functional circuit segment. Cutting at that mark preserves electrical integrity, keeps current limiting intact, and makes reconnection predictable. For clean project execution, treat cut lines as part of a bigger specification: voltage choice, power headroom, layout planning, sealing method, and compliance references—then select a manufacturer who can support the full lighting solution, not only the strip itself.