Minor Custom Tweaks

Calvin Lin
2016/05/12 (updated: 2026/08/18)

Minor tweaks to better suit your body shape

Make the pouch fit you better

Based on the most protruding point of the pouch — Pouch Tweaks example: Pouch +1cm × 2

Adjust the depth according to bulge pouch, seamless front, or bottom seam construction.

Bulge pouch can be adjusted up to ±2 cm × 2.

Example note: Pouch +1cm × 2 ｜ Pouch -1cm × 2

Or, in the shopping cart, click the quick button Pouch +1 or Pouch -1 in the item note field. The system will automatically enter Pouch +1cm ×2 or Pouch -1cm ×2. After editing, click Update Cart to save.

Modification Item	Applicable Type	Adjustment Range	Notes	Fee
Front Pouch Depth	Bulge pouch / Seamless front / Bottom seam	±1 cm × 2 Bulge pouch up to ±2 cm × 2	- Seamless front affects fit — avoid unless necessary - Bottom seam affects support — avoid unless necessary	Free

Height difference changes the wearing feel

Four back rise height options for iSwim underwear and swimwear — Back Tweaks example: Y1 change to Y0

From low rise to extreme low rise, freely adjust the back rise height to find the proportion that suits you best.

Special cuts and ruched styles require additional fees.

Example note: Back Change: Y0 (Note: Y0 is about 2 cm higher than Y1.)

Or, in the shopping cart, click the quick button Back in the item note field. The system will automatically enter Back Change: . Then add Y0 after it. After editing, click Update Cart to save.

Modification Item	Applicable Type	Adjustment Range	Notes	Fee
Back Rise Height	Thongs	Height 0–3 interchangeable Special Y4–7 interchangeable, V4–7 interchangeable e.g. Y2→Y0 / V1→V2 / Y6→Y5	- Standard styles cannot be swapped with special thongs (Y5 / Y6 / V5 / V6 / M types)	Free swap for thongs in same price range (C / T / D) Upgrading to Y / E / V incurs +NT$30–60
Back Rise Height	Briefs	Height 0–3 interchangeable (shirred 4–7 interchangeable) e.g. B2→B0 / N1→N2 / A6→A5	- Standard briefs upgrading to special briefs (U / N / O / J) require paying the difference	Free swap for briefs in same price range (F / B / H / A) Ruched special finish +NT$60–90
Back Panel Replacement	Briefs & Thongs	Back panels of the same price range (including briefs & thongs) can be swapped for free, height may also be changed at the same time	- Different back panels can be swapped by paying the price difference - Special cuts (Y5 / Y6 / V5 / V6 / M types) cannot be swapped with standard styles	Special finish +NT$30–90

Perfect snugness, effortless wear

Thin strap waist can be increased or reduced — Thin Strap Waist Tweaks Example：Waist +1cm × 2

8 mm straps or 15 mm edges can be fine‑tuned for a better waist and leg fit.

Example note: Waist +1cm × 2 ｜ Waist -1cm × 2

Or, in the shopping cart, click the quick button Waist +1 in the item note field. The system will automatically enter Waist +1cm ×2. If you need to reduce the waist, change +1 to -1. After editing, click Update Cart to save.

Modification Item	Applicable Type	Adjustment Range	Notes	Fee
Thin Strap / Thin Edge Waist	8 mm strap / 15 mm edge	±1 cm × 2 (±4 cm total)	- 8 mm strap fits tighter than 15 mm edge - First‑time 8 mm buyers: add +1 cm × 2 for comfort	Free

Stable wide waist, adjusted for comfort

Wide elastic waistband length can be adjusted by 1 inch — Wide Waistband Tweaks Example: Elastic +1 inch

For 2 cm or 1″ wide elastic briefs, waistband length can be increased or reduced by 1 inch.

No fabric adjustments available.

Example note: Elastic +1 inch ｜ Elastic -1 inch

Modification Item	Applicable Type	Adjustment Range	Notes	Fee
Wide Elastic Waist	2 cm / 1″ elastic briefs	±1″ (elastic length only)	No fabric adjustment available	Free

Extreme sizes, still adjustable

S and XXL size thin strap swimwear waist adjustments — XXL size Swimwear Tweaks Example: Waist +1cm × 2

For a better fit, the waist can be reduced for size S or increased for size XXL.

Available only for thin-edge and thin-strap swimwear.

Example note: Waist -1cm × 2 ｜ Waist +1cm × 2

Modification Item	Applicable Type	Adjustment Range	Notes	Fee
S / XXL Special Sizes	8 mm / 15 mm strap swimwear	±1 cm × 2	- S reduced ≈ XS - XXL increased ≈ XXXL	Free

Wide waistband, keep it original

Wide waistband swimwear adjustments not available

Due to its special pattern, wide waistband swimwear cannot be modified. Keeps the original support and style proportions.

Modification Item	Applicable Type	Adjustment Range	Notes	Fee
Wide Waistband Swimwear	2 cm wide waistband swimwear	Not available	Special pattern	N/A

🔧 Size Adjustment Policy

Each iSwim design is precision-cut based on human ergonomics. Even a 1 cm change can affect overall tension, pouch curvature, and waistline balance.

Our “minor adjustment” service is limited to reasonable manual adjustments. The maximum adjustment range is ±2 cm, and requests of 0.5 cm or less cannot be accepted.

We once had a customer request an adjustment of 0.15 cm. While this may look precise on paper, it is already below the range that can be reliably controlled with stretch fabrics, elastic tension, and manual sewing.

For this reason, we set the rule that requests of 0.5 cm or less cannot be accepted. This is not because we are unwilling to make adjustments, but because 0.5 cm may already fall within normal sewing tolerance, making it impossible to guarantee that the requested difference can be consistently reflected in the final fit.

Please note —
iSwim is not a made-to-measure tailor service. We specialize in precision fit engineering that balances comfort and sex appeal. Our goal is to maintain consistent wear feel and sculpted curves, not endless modifications.

✂️ We love a good challenge, but please remember — we use sewing machines, not laser cutters.
Some customers seem to think we are Tom Cruise, but this is not Mission: Impossible — Sewing Edition. 😄

Notice of Little Modification

Please make notes according to the examples above, do not create your own terms to avoid order delays.
Little modifications can only be used for semi-customized ordering, not applicable to pre-made or stock products.
The size washing label will keep the original.
The small modification was originally only open to VIP members and above, because we sell to more than 60 countries around the world and have many different body types, therefore we started opening it to all members since November 2018.
Due to limited manpower, since June 2011, modifications that must be made separately pattern is not accepted (for example: waist height, hip width, combination of different styles, etc.), only little modifications to the waist circumference and front pouch are accepted.
The little modification is not tailor-made, and there will be some differences in the wearing of different fabrics. After shipment, we will not accept any replacement requirements that do not meet the requirements. There is no additional charge for little modifications, but please be sure to read the instructions and cooperate carefully. This site will adjust or terminate the service depending on the situation.

Minor Custom Tweaks FAQ

Can the pouch space be increased or reduced?

Yes. Depending on the front construction, small pouch adjustments can be made. Common note formats include Pouch +1cm × 2 or Pouch -1cm × 2. Bulge pouch styles can be adjusted up to ±2cm × 2.

Can the back rise height be changed?

Yes. Most standard back pieces in heights 0, 1, 2, and 3 can be interchanged. Some special back styles can also be adjusted within the same series. Price differences or additional fees may apply to special cuts or finishing.

Can the waist of thin strap or thin edge underwear be adjusted?

Yes. Underwear with 8mm straps or 15mm thin edges can usually be adjusted by ±1cm × 2 at the waist. First-time buyers of 8mm strap styles who prefer a less tight fit may consider adding +1cm × 2.

Can the waist of wide waistband underwear be adjusted?

Yes. Underwear with a 2cm or 1-inch wide elastic waistband can have the elastic length adjusted by ±1 inch. This adjustment changes only the elastic length and does not add or remove fabric.

Can S or XXL thin strap swimwear be adjusted further?

Yes. For thin edge and thin strap swimwear, size S can be reduced further and size XXL can be increased further. The standard adjustment range is ±1cm × 2.

Can wide waistband swimwear be adjusted at the waist?

No. Wide waistband swimwear uses a special pattern and construction, so waist adjustments are not available.

What is the smallest adjustment iSwim accepts?

Requests of 0.5cm or less are not accepted. Stretch fabrics, elastic tension, and manual sewing all have normal production tolerances, so very small requested differences cannot be reproduced consistently.

What is the maximum range for minor tweaks?

Minor tweaks are generally limited to a reasonable range of up to ±2cm. Adjustments beyond the existing pattern range may require a completely new pattern and are therefore not included in the minor tweak service.

Are minor custom tweaks the same as made-to-measure tailoring?

No. Minor custom tweaks are limited manual adjustments made within existing iSwim patterns. They are not made-to-measure tailoring, and differences in fabric stretch may still affect the final fit.

Do minor custom tweaks require an extra fee?

Standard waist and pouch adjustments are generally free. Back piece changes, special cuts, ruching, and other special finishing may require an additional fee or price difference.

※Minor tweak availability and adjustment ranges will be updated on this page whenever services or conditions change. Last updated: July 15, 2026.