400 GSM Hoodie Manufacturer: Heavyweight Fleece Explained

400 GSM hoodie manufacturer programs use cotton fleece or french terry weighing about 380–420 GSM after finishing, often in 100% cotton with a 2x2 rib of 320–420 GSM. Weight should be checked within ±5% after washing; sampling usually takes 10–20 days and bulk 30–45 days, while MOQ depends on style and fabric.

"400 GSM" has become shorthand for a premium heavyweight hoodie. Brands use it on product pages because customers associate it with thickness and quality. But the number alone does not guarantee a good hoodie: how the weight is measured, what the fabric is made of and how it is finished matter just as much. This deep dive explains what a 400 GSM hoodie manufacturer should deliver and how to specify it properly.

What is a 400 GSM hoodie manufacturer?

A 400 GSM hoodie manufacturer is a hoodie factory that produces hooded sweatshirts in heavyweight fleece or french terry weighing about 400 grams per square metre, typically 380–420 GSM after finishing, with matching heavy rib, a structured hood and reinforced construction. A finished size M usually weighs around 750–950 g, and bulk production normally takes about 30–45 days after sample approval.

How GSM is measured, and why it matters

GSM is measured by cutting a 100 cm² circle from the fabric and weighing it. The result depends on when the sample is taken. Greige fabric straight from the knitting machine, finished fabric after dyeing and brushing, and fabric after a garment wash can all weigh differently. A supplier quoting "400 GSM" before finishing may deliver noticeably lighter fabric in the garment. Ask for GSM measured on finished fabric, or after wash for garment-dyed hoodies, and agree a tolerance such as ±5%.

Read our hoodie fleece GSM guide for how different weights feel, and hoodie GSM quote variables for how weight shows up on a quote.

Fleece or french terry at 400 GSM?

Both are made at this weight. Brushed fleece has a soft, napped inside and feels warmer; loopback french terry has visible loops inside, feels drier and usually holds a cleaner structure after garment dye. At 400 GSM, french terry gives a boxy, architectural silhouette, while fleece feels plusher. Our fleece vs french terry buyer guide compares them in detail.

Construction details for heavy hoodies

Heavy fabric changes how a hoodie should be built:

• Rib: use a heavy 2x2 rib, around 320–420 GSM, so cuffs and hem do not look thin next to the body.
• Hood: a double-layer hood in self fabric gives a full, standing shape; single-layer hoods in heavy fabric can look stiff.
• Seams: heavier needles and adjusted stitch density stop seams from puckering; flatlock or coverstitch on key seams reduces bulk.
• Drawcords: wider flat or round cords look in proportion with heavy fleece; some brands skip cords for a clean look.

Sourcing 400 GSM hoodies? Weavnora makes heavyweight hoodies in 380–450 GSM fleece and french terry. See our heavyweight hoodies page and request a quote with your fit and colours.

320 GSM vs 400 GSM hoodie: which option fits?

Many brands carry a mid-weight and a heavyweight hoodie. Use these selection criteria to place each one.

The trade-offs are comfort range and cost versus perceived quality. A 320 GSM hoodie is easier to wear year-round and cheaper to make and ship, while a 400 GSM hoodie feels premium and holds its shape but costs more in fabric and freight and can be too warm for some markets. Weights around 450–500 GSM exist too, but they get stiff and are mainly used for statement pieces.

Washes and decoration on heavy fleece

Garment dye, enzyme and mineral washes work well on 400 GSM cotton fleece and french terry, though washing can lower or raise measured GSM slightly and shrinks the garment by around 3–5% if the fabric is pre-shrunk. Heavy fabric is an excellent base for embroidery and puff print because it does not pucker easily. Large screen prints are also stable on heavy french terry.

What changes in cost and freight?

Fabric is priced by kilo, so a 400 GSM hoodie uses more kilos of fabric per piece than a 320 GSM one, and fabric is already the largest line on a hoodie quote. Sewing is slightly slower on thick fabric. Freight also increases because the finished hoodie is heavier and bulkier, which matters most for air shipments. If you sell into warm markets or ship by air, compare both weights before committing. For a side-by-side example of blank heavyweight options, see blank heavyweight hoodies wholesale.

How do you check a 400 GSM sample?

Ask for a GSM test on the actual sample fabric and repeat it after three home washes. Weigh the finished hoodie and record it. Check rib recovery, hood shape, seam bulk at the shoulders and armholes, and pilling on the inside. Measure against your chart before and after wash. Keep the test results with the approved sealed sample so bulk fabric can be checked against the same figures.

Is 400 GSM the right weight for your customers?

It depends on climate, price point and style. Streetwear customers in cold and temperate markets often prefer heavy, boxy hoodies, while customers in warm climates or who layer under jackets may prefer lighter weights. Look at your returns and reviews: if customers mention "thin" or "loses shape", heavier fabric may help; if they mention "too hot" or "stiff", a lighter fabric may sell better. For more hoodie guides, visit the custom hoodie and sweatshirt manufacturing hub.

How should you describe 400 GSM on your product page?

If you sell the hoodie as 400 GSM, make sure the claim matches the finished product. State the fabric composition, the construction (fleece or french terry) and whether the weight refers to finished fabric. Keep the GSM test report from your approved sample and bulk fabric on file in case customers or marketplaces ask. Adding the finished garment weight in grams for one size is another helpful detail, because many customers understand garment weight more easily than fabric GSM.

400 GSM hoodie manufacturer: typical specs and key numbers

These are typical industry estimate ranges, not quotes; confirm actual figures with your supplier for your fabric, quantity and destination.

Key takeaways

• 400 GSM means about 400 grams per square metre of finished fabric, usually 380–420 GSM.
• Ask for GSM measured after finishing or after wash, with a ±5% tolerance.
• Match heavy fabric with heavy rib, a double-layer hood and adjusted seams.
• Heavier fabric raises fabric and freight cost but lifts perceived quality.
• Test GSM and measurements again after three washes.

Request a 400 GSM hoodie quote

Send your fit reference, preferred fabric (fleece or french terry), colours and decoration through our quote request form. We reply with sampling time, price and MOQ, which depends on style and fabric.