丸編みと横編み：量産アパレルの生産性を左右する製造上の違い

Key Sourcing Takeaways

• Circular knitting produces continuous tubular fabric at high speed — suited for volume basics such as jersey, interlock, and rib.
• Flat knit produces shaped panels with greater stitch complexity — better matched to structured or pattern-intensive styles.
• The two machine types differ in cutting waste behaviour, fabric width handling, and MOQ efficiency, all of which affect your landed cost.
• Misidentifying machine type at the sourcing stage can result in width mismatches, pattern limitations, or unnecessary resampling.

Circular knit and flat knit are not interchangeable terms for "knitted fabric." They describe two distinct production systems with different output logic, fabric dimensions, and cost structures. Sourcing teams that conflate the two often encounter spec mismatches or sampling delays that could have been avoided before the first purchase order was placed.

How Circular Knitting Produces Fabric — and What That Means for Bulk Orders

Circular knitting machines operate on a rotating cylinder of needles, producing fabric in a continuous spiral. The output is a seamless tube, which can be used in tubular form or slit open to a flat width depending on the end use. This continuous-loop process is optimised for speed: machines can run with minimal interruption across long production shifts.

The fabric types most commonly produced on circular machines include single jersey, interlock, rib, and piqué. These are the structural foundations for core casualwear, underwear, activewear, and layering programmes. Because needle count and machine diameter remain fixed during a run, output is highly consistent across large yardages — a key requirement for bulk colour programmes where shade variation needs to be controlled.

For sourcing teams, the circular knit model aligns best with high-volume, repeatable SKUs. Long production runs reduce setup costs per kilogram, and the continuous output means lead times can be tighter when capacity is committed. The trade-off is design flexibility: circular machines are optimised for consistent stitch structures, not for the kind of three-dimensional shaping or pattern complexity that requires needle-by-needle control.

One practical consideration when specifying circular knit fabric is edge behaviour. Because the fabric is formed as a tube, the cut edges can carry a curl tendency depending on the fibre content and fabric weight. This is a standard variable in cut-and-sew operations, and should be factored into cutting allowance calculations when reviewing fabric specifications.

Where Flat Knitting Adds More Control Than Circular Production

Flat knitting machines move a carriage back and forth across a horizontal needle bed, building fabric row by row in a flat sheet. Because each needle can be individually controlled during the pass, the machine can increase or decrease stitch count per row, transfer loops between needle positions, and switch between stitch structures within a single panel.

This needle-level control makes flat knitting better suited for shaped panels, cable relief, intarsia placement, and structured knitwear parts where stitch count changes within the panel. Circular knitting can still support repeat-based structures and some pattern development, but it is usually less efficient when the brief requires panel-level shaping or raised cable definition.

The flat knitting process is slower by design. What it trades in speed, it returns in construction specificity. For sourcing teams developing structured or design-led styles, this is not a disadvantage — it is the correct tool for the requirement. Sampling on flat machines also tends to involve shorter minimum sample lengths, which can make design iteration more manageable during development cycles. For complex flat-knit structures, digital sample review can also reduce communication gaps before physical sampling; SHIMA SEIKI’s virtual sampling system shows how flat knitting data can connect design review with machine production planning.

Flat knit output arrives as a pre-dimensioned flat panel. There is no tubular handling step, and edge curl is less of a factor. Width, however, is determined by the number of active needles and the machine's working width, which means specifying panel dimensions requires accurate needle count information at the brief stage.

Circular Knit vs Flat Knit: The Production Variables That Change Your Cost and Lead Time

When you compare circular knit vs flat knit across a sourcing brief, the differences that matter most are not aesthetic — they are operational. Below is a summary of the key production variables that affect order planning, costing, and supplier conversations.

MOQ behaviour: Circular knit production usually becomes more cost-efficient when setup time is spread across longer yardage or kilogram runs. Flat knit MOQ is more project-specific because panel complexity, yarn selection, and programming time can change the development cost. For Runtang orders, stock fabrics start from 1 roll (~23 kg) per colour, custom solid colors start from 200 kg per color, and general custom development starts from 1,000 kg; confirm the applicable MOQ during sampling because cable knit and shaped-panel projects may follow different requirements.

Gauge as the connecting variable: Both machine types use gauge (needles per inch) as a core specification parameter, but gauge ranges differ between them. Understanding gauge selection — and how it affects hand feel, stitch density, and production speed — is a prerequisite for writing accurate technical briefs for either machine type. A deeper explanation of gauge across machine types is covered in 編機のゲージ：風合い、編み目密度、生産速度をどう決めるか.

Cutting waste allowance: Circular knit fabric, particularly single jersey, can exhibit a roll tendency at cut edges due to the loop structure's tension balance. This is a normal characteristic and should be included in cutting efficiency calculations. Flat knit panels are less prone to this behaviour, though selvedge allowances still apply depending on construction.

Matching Machine Type to Your Sourcing Brief

The most efficient way to avoid machine-type mismatches is to build the distinction into your fabric brief from the start. Suppliers working at the factory level think in machine configurations, not generic categories — a brief that specifies the fabric structure and end-use application gives a clear enough signal to confirm machine suitability before sampling begins.

Here are three practical indicators that help identify which production system your requirement maps to:

• If your brief describes a smooth, consistent surface for volume basics (t-shirts, leggings, layering tops, polo shirts), circular knit is the natural starting point. Fabric types in this category include jersey, interlock, rib, and piqué.
• If your brief includes dimensional structure — visible cable columns, raised stitch relief, shaped panels, or multi-colour intarsia — flat knit is required. Fabric types include cable knit and complex structured constructions.
• If your brief spans both categories across a seasonal range, plan for separate sampling streams. Circular and flat knit development timelines, sample lengths, and bulk lead times do not operate on the same logic.

Runtang’s core production strength is in circular knit structures, including single jersey, interlock, rib, and piqué across multiple fibre compositions. For cable knit fabric and other flat-knit-style structures, the development route should be confirmed at the brief stage, including machine type, panel dimensions, yarn choice, and whether production is handled in-house or through a coordinated partner facility. Clarifying this early prevents specification drift between sampling and bulk.

When reviewing supplier capability for a mixed-machine range, confirm whether the supplier operates both machine types in-house or coordinates flat knit development through a partner facility. This affects both sampling timelines and the degree of direct quality control at the bulk production stage.

よくある質問

Is circular knit or flat knit better for high-volume basics orders?

Circular knit is the production system aligned with high-volume basics. Its continuous output, consistent stitch structure, and efficient setup amortisation across long runs make it the standard choice for jersey, interlock, rib, and piqué programmes. Flat knit production is slower and better matched to design-intensive styles where construction complexity is the primary brief requirement, not volume efficiency.

Can I source both circular and flat knit fabrics from the same supplier?

Yes, though confirm the supplier's direct production scope versus external coordination for each machine type. Some fabric mills operate both circular and flat knitting equipment in-house; others specialise in one system and manage the other through partner facilities. Sourcing both from a single point of contact is practical for range management, but it's worth understanding where each fabric type is actually produced before committing to bulk.

Runtang Tex produces circular knit jersey, interlock, rib and related knitted fabrics for apparel brands across Europe, North America and Australia. For cable knit or flat-knit-style requirements, contact us to confirm the development route and request samples.