The final hand, drape and durability of a collection are not determined by a single parameter: knit structure, weight, yarn type, finishing and certification together form a recipe. The same single jersey gives a light summer T-shirt with 130 g/m² combed yarn, while with 200 g/m² ring-spun yarn it produces an entirely different premium product. For this reason, instead of asking "which fabric is better", you should ask "which recipe for this product, this use and this target audience". This pillar page is the gateway to the detailed guides organised by product category, and it defines the common framework you can use when making a choice.
Guides by Product
T-Shirt Fabric Selection
Weight, combed/carded choice and print compatibility along the single jersey and interlock axis.
Sweatshirt and Hoodie Fabric
The warmth and drape balance of 2-thread, 3-thread and brushed structures.
Polo Fabric Selection
The shape retention, collar stability and weight ranges of pique knit.
Activewear and Legging Fabric
Elastane interlock/jacquard, moisture management and recovery performance.
Underwear and Baby Fabric
Skin contact, hydrophilic comfort and certified safety priorities.
Which five criteria should I evaluate in order when selecting a knit fabric?
A good fabric decision is made not through an abstract "quality" debate but by stacking five concrete layers. The first layer is end use: is the product an everyday T-shirt, an intensely sweaty training piece, or a baby bodysuit in contact with sensitive skin? This frames everything else. The second layer is weight (g/m²); within the same knit type, weight determines the product's heft, opacity and seasonality. For detailed thresholds you can refer to the weight and GSM guide.
The third layer is the fibre and yarn recipe: combed or carded, ring-spun or open-end, and will viscose, modal, polyester or elastane be blended with cotton? The fourth layer is finishing (finishing); the same greige fabric is transformed into a completely different product through brushing, mercerisation or compacting (Sanforising). The fifth layer is certification; if the target market requires OEKO-TEX, GOTS or GRS, this decision must be made at the very outset because it retroactively affects yarn sourcing.
| Layer | Defining question | Typical output |
|---|---|---|
| End use | How will it be worn, washed, how often? | Knit type and weight class |
| Weight | Is a light, medium or heavy hand wanted? | Target g/m² range |
| Fibre / yarn | What is the priority: hand, strength, stretch? | Cotton/blend, combed/carded, ring/OE |
| Finishing | Softness, lustre or stability — which one? | Brushing, mercerised, Sanfor, finish |
| Certification | What does the target market mandate? | OEKO-TEX / GOTS / GRS / OCS |
Which knit structure and weight range suit which product?
There are established pairings between product category and knit structure, because each knit behaves differently in drape, stretch and surface. Single jersey is single-layer, light and fluid; it is therefore the natural home of the T-shirt. Interlock, with its double-layer, balanced structure, gives a fuller fabric that is smooth on both faces; it stands out in premium T-shirts and pieces expected to hold their shape. You can find the distinction between the two in detail in the single jersey versus interlock comparison.
In polo shirts, the cellular surface of pique knit provides both breathability and collar shape retention. In the sweatshirt family, two- and three-thread structures are brushed with a single fleece yarn fed inward to create a napped, warm inner surface; three-thread is thicker and more insulating. In activewear, interlock or jacquard structures containing elastane are required for four-way stretch and recovery.
| Product | Typical knit | Typical weight (g/m²) | Standout property |
|---|---|---|---|
| Basic T-shirt | Single jersey | 120-200 | Lightness, drape |
| Premium T-shirt | Interlock | 180-220 | Fullness, shape |
| Polo | Pique | 180-240 | Surface, collar stability |
| Sweatshirt | 2-thread (brushed) | 220-320 | Soft inner face |
| Hoodie | 3-thread (brushed) | 280-420 | Warmth, volume |
| Legging / activewear | Elastane interlock / jacquard | 220-320 | Stretch, recovery |
These ranges are indicative; brand positioning can differ even within the same category. For example, while a promotional T-shirt is built on a cost-driven basis with 150 g/m² carded single jersey, a boutique brand's identical silhouette offers a completely different hand with 200 g/m² combed single jersey. For how weight tolerance is managed in production, take a look at the GSM tolerance concept and the weight guide.
How does fibre and yarn choice change the product's hand and durability?
At the same knit and weight, two fabrics can be perceived very differently purely because of yarn choice. In the combed process the short fibres are removed by combing, so the yarn is cleaner, lint-free and stronger; this means less pilling (pilling) and a smoother print surface. Carded yarn skips this combing step and therefore gives a more affordable but hairier hand. The choice between ring and open-end spinning systems similarly balances softness against cost/robustness.
The fibre blend, in turn, fundamentally determines the product's character. Pure cotton offers comfort and breathability; modal and viscose add a more fluid, silky drape; Tencel brings the advantage of moisture management and sustainability. Polyester and especially rPET provide durability, fast drying and a recycled-content claim. Elastane/spandex is decisive for stretch and shape retention even at proportions of just a few per cent; you can examine its effect in the knit structure in the elastane and spandex guide.
| Choice | What it brings | Cost / caution |
|---|---|---|
| Combed vs carded | Smooth, lustrous, durable surface | Higher yarn cost |
| Ring vs open-end | Soft, voluminous handle | OE is stronger but harsher |
| Modal / viscose addition | Fluid drape, silky hand | Wet strength and dimensional control |
| Polyester / rPET | Durability, fast drying | Moisture feel, anti-static need |
| Elastane / spandex | Stretch and recovery | Dyeing and heat-setting sensitivity |
How do finishing and dye/print decisions affect fabric selection?
A fabric's final hand is shaped far more in the finishing and finish processes than in its greige state coming off the knitting machine. Brushing naps and warms the inner surface of a sweatshirt, while mercerisation gives cotton lustre, dye uptake and strength. Sanforising and compacting manage dimensional stability, reducing the risk of shrinkage in washing. For this reason finishing is not an afterthought to fabric selection but a central component of the recipe.
The dyeing method, meanwhile, depends directly on fibre chemistry: reactive dyeing for cotton and cellulosic fibres, disperse dyeing for polyester, and pigment or garment-dye for surface effects and a vintage look. If colour consistency is critical, the colour fastness and ΔE side of the process must be defined from the outset; at KARCEM the target is carried from lab-dip approval through to production with a tolerance of ΔE<1. You can find how this entire dye, print and finishing chain is structured in the dyeing and printing guide.
How do certification and sustainability requirements prioritise the choice?
Sustainability certifications are not merely marketing labels; they are structural decisions that bind the supply chain retroactively. GOTS certifies organic content and the audit of the whole chain, GRS and RCS the recycled-content claim, and OEKO-TEX Standard 100 the harmful-substance limits in the finished product. Because these certifications begin with certified yarn, adding them midway through a project is usually not possible; they therefore sit at the very top layer of the selection framework.
In the European market, regulations such as ESPR and the Digital Product Passport are moving towards making traceability mandatory; MRSL/ZDHC compliance, meanwhile, governs chemical management. We address how to integrate these requirements into collection planning in the sustainability and regulation guide, and the carbon-footprint side of the certifications in our GOTS, RCS and carbon article.
How is the fabric decision finalised during the sampling and ordering process?
Even when the selection framework is completed on paper, final approval comes with physical verification. The lab-dip stage confirms the colour, while the sewing sample confirms the hand, drape and stitching behaviour. If these steps are skipped, costly-to-reverse surprises can arise in production. MOQ, lead time and delivery terms vary according to product complexity, number of colours and certification requirements, so rather than a fixed list they are clarified per project; you can find how this process works on the MOQ, sampling and delivery process page and in the sourcing guide.
KARCEM's model provides a decisive advantage here: because we knit greige in-house and coordinate dyeing, printing and finishing through a vetted contract network under a single point of contact, every layer of the fabric recipe — weight, fibre, finishing, colour — is optimised within one coordinated flow and responsibility is not dispersed. This preserves consistency in the transition from sample to bulk production. For details specific to your product category you can move to the relevant guide from the cards above, and for the general fabric family you can review the knit fabric guide and our fabric portfolio.
To keep this whole guide in a single file, download the PDF version of this guide.
Frequently asked questions
Which five criteria should we evaluate, and in what order, when selecting a knit fabric?
In order: end use, weight, fibre/yarn recipe, finishing and certification. First define how the product will be worn and laundered; this sets the knit structure and weight class. Fibre and finishing govern hand feel and performance, while certification closes off market access. The layers stack on top of one another; skipping a step leads to a flawed recipe and to surprises in production that are costly to reverse.
Which knit structure and weight range suit which product?
For a basic T-shirt, single jersey (120-200 g/m²); for premium tees and products that need structure, interlock (180-220); for polos, piqué (180-240); for sweatshirts, 2-thread fleece (220-320); for hoodies, 3-thread fleece (280-420); for leggings and activewear, spandex interlock/jacquard (220-320). These are industry norms; the final figure is settled according to end use and brand positioning.
How does the difference between combed and carded yarn show up in the fabric's hand feel and durability?
In combed yarn the short fibres are combed out and removed; the yarn is cleaner, lint-free and stronger, which means less pilling and a smoother print surface, but the yarn cost is higher. Carded yarn skips this combing step; it is more economical but gives a hairier, more rustic hand. The choice is made according to the product's priority.
What does adding polyester, modal/viscose or spandex to the fibre blend change in the product?
Pure cotton offers comfort and breathability; modal/viscose adds a more fluid, silky drape but requires attention to wet strength and dimensional control; Tencel brings a moisture-management advantage. Polyester and rPET deliver durability and fast drying but can create a clammy feel and a need for anti-static treatment. Spandex/elastane, even at a few percent, is decisive for stretch and recovery, and demands care in dyeing/heat-setting.
Why do finishing and the dyeing method affect fabric selection right from the outset?
Finishing is the final layer that determines the hand feel and stability of the greige fabric: brushing softens and warms, mercerisation gives lustre and strength, and sanforising controls shrinkage. The dyeing method depends on the fibre chemistry; reactive for cotton, disperse for polyester, pigment/garment-dye for a vintage effect. These decisions are not a step bolted on afterwards but a central part of the recipe.
What tolerance does KARCEM target for colour consistency, and when should the certification decision be made?
At KARCEM the target is carried from lab-dip approval through to production with a ΔE<1 tolerance; where colour consistency is critical, the process is defined around this axis from the very start. The certification decision must be made at the outset, because a GOTS, GRS/RCS or OEKO-TEX claim begins with certified yarn and dictates yarn sourcing retroactively; adding it midway through a project is usually not possible.