Best Fabric for T-Shirts: How to Choose Between Jersey, Interlock and Slub

Most T-shirt fabric decisions start with fiber — cotton or polyester, combed or ring-spun. That's the wrong starting point. Two T-shirts built from identical cotton yarn can perform very differently based on knit structure alone. Before sampling, brand buyers need to evaluate single jersey, interlock, and slub knit on structure-level variables: weight range, opacity, shrinkage behavior, and print compatibility.

Why Knit Structure — Not Fiber — Is the First T-Shirt Sourcing Variable

Fiber type sets the baseline, but knit structure determines how a T-shirt performs across wash cycles, printing runs, and bulk reorders. Single jersey and interlock can share the same cotton yarn count, yet produce fabrics that differ in weight, transparency, and dimensional stability after washing. For brand buyers building repeatable collections, this distinction matters more than it appears at the sampling stage.

A fabric that looks right in hand may shrink asymmetrically, curl at the edges, or show transparency under light — all of which trace back to structure, not fiber. Confirming the knit construction before approving a sample avoids downstream problems in bulk production. The three structures most relevant to T-shirt sourcing — single jersey, interlock, and slub jersey — each carry specific trade-offs that should map directly to the garment's end-use and production volume. As a starting reference, single jersey often falls around 120–200 GSM, interlock around 180–280 GSM, and slub jersey around 150–230 GSM, depending on yarn count, composition, and finishing.

Single Jersey: Lightweight, Print-Ready, and Built for High Volume

Single jersey is knitted on one needle bed, producing a fabric with a smooth face and a looped back. It is the most widely used structure in T-shirt production — particularly for high-volume basics, graphic tees, and printed styles — and is available across a broad weight range that can run from around 120 to 200 GSM depending on yarn count, composition, and finishing.

Its open construction makes it compatible with most print methods, including reactive printing and pigment printing. The trade-off is a higher tendency for cut edges to curl, and a greater susceptibility to spirality and shrinkage in bulk washing tests. Buyers sourcing print-heavy programs should confirm that shrinkage and spirality results fall within tolerance during pre-production sampling, rather than relying on structure assumptions.

We manufacture jersey knit fabric across a range of cotton, polyester, and blended compositions, with sampling available before bulk commitment.

Interlock for Premium T-Shirts: Opacity, Stability, and a Heavier Hand

Interlock is a double-knit construction produced on two opposing needle beds. Both faces of the fabric appear identical, and the doubled structure results in a denser, heavier hand — typically ranging from around 180 to 280 GSM depending on composition and finishing. The construction also delivers significantly better opacity than single jersey, which becomes a practical quality consideration for styles where fabric show-through under light is unacceptable.

Dimensionally, interlock knit fabric tends to be more stable: lower curl tendency at cut edges, better shrinkage resistance, and more consistent lay-flat behavior during spreading and cutting. For premium basics or brand-label programs, it is often the safer structure when opacity and repeatable cutting behavior matter. OEKO-TEX® Standard 100 certified options are available. Please confirm certification requirements at the time of sampling.

Slub Jersey: When Surface Texture Is the Design Angle — and What to Watch in Bulk

Slub jersey uses yarn with intentionally irregular thickness, producing a surface with a natural, textured appearance. For T-shirt programs positioned around vintage aesthetics or visible texture as a design statement, slub knit fabric offers a differentiation that plain jersey cannot replicate.

The primary sourcing consideration is batch consistency. Because the slub character is inherently irregular, color uptake can vary slightly across the fabric surface and between production lots. Brands running slub programs should request lab dips, shade-band approval, and pre-production samples before bulk. Print compatibility also needs testing: uneven yarn thickness may affect fine-line registration or heavy graphic coverage. Slub jersey is usually safer for solid dye, wash-effect, vintage-look, or lower-coverage print programs where surface variation supports the design rather than reading as a defect. For a deeper look at slub performance in T-shirt applications, see our article on slub knit fabric for t-shirts.

Jersey vs Interlock vs Slub — Quick Comparison for Sampling Decisions

Use the table below to align fabric structure with your garment specs before requesting samples.

Feature	Single Jersey	Interlock	Slub Jersey
Approx GSM Range	120–200 GSM	180–280 GSM	150–230 GSM
Opacity	Lower — show-through possible	Higher — solid coverage	Varies with slub density
Print Compatibility	Good — most methods	Good — most methods	Limited — uneven surface
Shrinkage / Spirality	Higher tendency	Lower tendency	Depends on construction
Edge Curl	More pronounced	Minimal	Moderate
Best Application	Basics, graphic tees, high-volume	Premium basics, structured tees	Texture-forward, dye-only styles

All GSM ranges are direction-only references. Actual weight varies with yarn count, composition, and finishing. Confirm against your tech pack specifications during sampling.

FAQ

What GSM should I specify for a mid-weight premium T-shirt?

For a premium T-shirt in interlock, a weight range of around 200–240 GSM can serve as a starting reference point for sampling — but the appropriate figure depends on fiber content, garment construction, and end-market expectations. We recommend evaluating hand feel and opacity against your reference garment during the sampling stage rather than specifying a target weight in isolation.

Does interlock shrink less than single jersey in bulk washing tests?

Interlock generally shows better dimensional stability than single jersey due to its double-knit construction, but shrinkage behavior varies with fiber content, yarn tension, and finishing processes. Confirming shrinkage rates against your acceptable tolerance — using the washing standard called out in your tech pack — is part of pre-production approval, not something to assume from structure alone.

Can a slub jersey be dyed to a consistent color across reorders?

Slub yarn's irregular surface absorbs dye at varying rates, which may produce slight tonal variation within a roll and between production lots. This is manageable with shade band controls and lot-to-lot approval protocols, but brands should factor this into their QC workflow before confirming slub as a reorder fabric. Request sample sets across single jersey, interlock, and slub knit before committing to a structure. Runtang Tex supports custom compositions, GSM ranges, and color development for bulk T-shirt fabric sourcing.