LQ-4C & LQ-4CH
Four Colors. Brand-Level Printing.

2-color printing produces a brand name, text and simple graphics in two distinct colors — typically a background color and a foreground color. There are no gradients, no tonal transitions, and no multi-color logos. 4-color printing uses a near-CMYK process (cyan, magenta, yellow, black) that can reproduce gradients, tonal photography, multi-color brand logos, and complex graphic designs. The practical difference for a bag converter is this: if your customers are retail brands, food service chains, or garment retailers, they almost always require 4-color printing as a minimum standard. If your customers are industrial buyers, logistics companies, or internal-use packaging buyers, 2-color is typically sufficient.

Registration is the alignment of each color station's print to the same position on the substrate. In 2-color printing, a misregistration of 0.5mm between two colors produces a visible but often acceptable color shift. In 4-color printing, the same 0.5mm error affects all four colors simultaneously — the result is color fringing on every edge of every printed element, making the entire design look blurred or out of focus. 4-color registration is harder because there are four stations to align instead of two, and because the error compounds: if station 1 is 0.2mm off and station 3 is 0.2mm off in the opposite direction, the effective misregistration between those two colors is 0.4mm. This is why drive system quality (synchronous belt vs. VFD) and substrate tension consistency matter more in 4-color printing than in 2-color.

8 m/min is the slow-speed calibration range used during job setup — not a production speed. When operators start a new job on the LQ-4CH, they run the machine slowly to check color registration, verify ink viscosity and density, confirm drying temperature, and make fine adjustments before ramping up to production speed. This calibration phase typically takes 10–20 minutes per job change. Once the machine is dialed in, production speed runs at 80–100 m/min. The 8 m/min figure is published because it defines the machine's full operating range — but for production planning purposes, use 80–100 m/min as your throughput basis.

The LQ-4C (800mm model) has a machine footprint of 4,200 × 1,800 × 2,400mm. Allow at least 1m operator clearance on all sides plus feed and exit space for material rolls — a practical floor allocation of approximately 7m × 4m. The LQ-4CH is significantly larger at 6,800 × 2,000 × 2,900mm. Allow a minimum floor length of 9–10m. If you are currently running a 2-color line and considering an upgrade: the LQ-4C is 2,300mm longer than the LQ-2C (4,200mm vs. 1,900mm), and the LQ-4CH is the same length as the LQ-2CH (both 6,800mm) but taller (2,900mm vs. 2,300mm). Ceiling height and floor load capacity (5,000–6,000 kg for LQ-4CH) must both be confirmed before ordering.

Anilox rollers are precision-engraved cylinders that meter the exact volume of ink transferred from the ink tray to the printing plate at each station. The surface is covered with microscopic cells — the cell volume and line count (measured in lines per centimetre, LPC) determine how much ink is delivered. Over time, these cells wear and become partially blocked with dried ink, reducing transfer volume and causing color density to drift. Replacement frequency depends on production volume, ink type, and cleaning practices — in a high-volume operation running water-based inks with proper cleaning, anilox rollers typically last 2–5 years before measurable cell wear affects print quality. LayerQuestar supplies replacement anilox rollers as standard spare parts. Confirm the specification (cell volume and LPC) for your specific substrate and ink system with the LayerQuestar after-sales team when ordering your machine.

The LQ-4C is the more appropriate starting point for operators transitioning from 2-color to 4-color printing. Its lower operating speed (50 m/min maximum) gives operators more time to observe and adjust color registration, ink viscosity, and drying temperature during a run. The slower speed also means that when a registration error occurs — and it will, during the learning phase — less substrate is wasted before the operator identifies and corrects it. The LQ-4CH's higher speed and additional systems (EPC, extended oven, dual tension control) require operators who already understand 4-color registration fundamentals. LayerQuestar provides on-site commissioning support and operator training for both series — confirm the training scope and duration with the sales team when ordering.

A full job changeover on a 4-color machine — replacing all four plates, cleaning all four ink trays and anilox rollers, loading new ink, and re-calibrating registration — typically takes 45–90 minutes depending on operator experience and the complexity of the new design. This is significantly longer than a 2-color changeover (20–40 minutes). The practical implication: if you run many different designs in small quantities, the changeover time per job becomes a significant portion of your total machine time. In this scenario, the LQ-4C's lower speed is less of a disadvantage, because the machine is frequently stopped for changeovers anyway. The LQ-4CH's throughput advantage is most pronounced on long continuous runs of the same design.

4-color printing covers approximately 90–95% of plastic bag printing requirements. The specific scenarios where 6-color becomes relevant are: (1) your customer's brand guidelines specify exact Pantone spot colors that cannot be reproduced accurately through CMYK process mixing — common in premium cosmetics, luxury fashion, and international retail chains with strict brand color standards; (2) you are printing on substrates where CMYK gamut is limited and extended color gamut printing is contractually required; (3) you are targeting the high-end gift bag or premium carrier bag market where color accuracy is a competitive differentiator. If none of these apply to your current customer base, 4-color is the right starting point. You can always add a 6-color line later as your market moves upmarket — it is a separate machine investment, not an upgrade to the 4-color line.