T-shirt tech pack: measurements and details

The essential measurements

Your size chart is the heart of the tech pack. For a t-shirt, the points of measure that matter most are:

• Chest width: measured flat, 2.5 cm below the armhole.
• Body length: from the highest point of the shoulder to the hem.
• Shoulder width: seam to seam across the back.
• Sleeve length: from the shoulder seam to the sleeve opening.
• Neck opening: the width of the collar, edge to edge.
• Hem and sleeve opening widths.

Fit and tolerance

Decide the fit before the numbers: regular, oversized or fitted change every measurement. An oversized tee typically adds 8 to 15 cm of chest width compared to a regular fit and drops the shoulder seam down the arm. Write the intended fit at the top of the tech pack so the pattern maker understands the silhouette, not just the numbers.

Add a tolerance for each measurement — usually ±1 cm for knits. Without tolerances, a factory cannot tell a defect from a normal variation.

Fabric and weight

Specify the composition (100% cotton, cotton-elastane blend…), the knit type (single jersey is the standard) and the weight in GSM. A light tee sits around 140–160 GSM, a standard tee around 180–200, and a heavyweight streetwear tee at 220 GSM and above. The weight changes the drape, the opacity and the price — never leave it to chance.

If you want a specific hand-feel — slub, brushed, garment-dyed — say it explicitly, and ask for fabric swatches before the sample.

Collar, stitching and finishing

The collar makes or breaks a t-shirt. Specify the rib type (usually a 1×1 rib with elastane for recovery), its width, and whether you want a taped shoulder-to-shoulder seam inside — the detail that keeps the neckline stable over time.

For construction, cover the side seams (overlock), the hems (twin-needle coverstitch is the standard for a clean finish) and any topstitching. If your design includes prints or embroidery, add their artwork, dimensions and exact placement measured from reference points — for example, "centre of print 8 cm below the collar seam".

Labels and packaging

List the main label (woven or printed, its artwork and position), the care label with washing instructions and composition, and the size label. Finish with packaging: folding, polybag, and carton markings if you have them.

In Atelia, the t-shirt tech pack is generated from your design with guided fields for each of these points — you fill in your choices, the app structures the document the way factories expect it.

Prints and embroidery placement

A t-shirt is often a canvas for a print, and placement is where beginners get surprised. Always give the print's dimensions and its position from fixed reference points: the centre chest print is typically placed 8 to 10 cm below the collar seam; a back print is measured from the back collar. Specify the technique too — screen print, DTG, puff print or embroidery all behave differently on jersey, and the factory needs to know which one you expect.

For embroidery, add the stitch count or at least the design's size and density, and ask for a stitch-out sample on the actual fabric before the full sample.

Common t-shirt mistakes

The classics: forgetting the collar rib specification, so the neckline waves after two washes. Choosing a fabric weight by photo instead of by GSM. Skipping the tolerance column, then arguing with the factory over a 1 cm difference. And placing a print without reference points, so it lands two centimetres too low on every piece. Each of these is one line in the tech pack — write them once and they protect every order.

Sizes and grading

Your size chart needs more than one size. Grading is the rule that turns your base size into the full range: typically +4 to 5 cm of chest width and +2 cm of length per size for a t-shirt. You can write the full chart yourself, or give the base size and the grading rule and let the pattern maker compute the rest — but say which one you expect. And decide your range early: an XS-to-XXL chart is a different production plan than an S-to-L launch.

If your brand targets a specific audience — taller, plus-size, cropped fits — the grading is where that promise becomes numbers.

One last habit that saves money: wash-test your sample before approving it. Jersey shrinks and twists, and the amount depends on the fabric and the finishing. Note the before and after measurements in your project — if the shrinkage is unacceptable, the factory can pre-shrink the fabric or adjust the pattern, but only if you caught it at the sample stage.