March 31, 2026 | Supply Chain Insights

As the situation in the Strait of Hormuz continues to develop, we have received a number of inquiries from our partners regarding cost trends and sourcing strategies. Based on the latest available information, we have put together the following observations and considerations—offered not as definitive guidance, but as a perspective we hope may be useful in your own planning.

The Strait of Hormuz has now been closed for over 32 days. Recent developments indicate that Iran and Oman are finalizing a transit fee structure for vessels passing through the strait—with fees expected to be high, and with vessels from Israel, the United States, and allied nations likely to be excluded. This suggests that rather than a full reopening in the near term, we may be entering a phase of “selective access with elevated transit costs.”

What might this mean for the apparel industry? More than 60% of the world’s fabrics are synthetic—polyester, nylon, spandex—all derived from petrochemical feedstocks. If crude oil transport costs are permanently elevated, higher synthetic raw material prices could shift from a short-term shock to a longer-term reality.

This article offers three things:

1. A look at how cost transmission typically works—and why the window for locking in prices may be narrowing

2. Which categories may be most affected

3. A few considerations that buyers may want to keep in mind

I. From Crude Oil to Garments: How Does Cost Transmission Work?

Turning crude oil into finished garments involves multiple stages. Each stage carries inventory buffers—an important factor in understanding timing.

What High Transit Fees Might Mean

According to recent reports, Iran and Oman are developing a high-cost transit fee structure with exclusions for certain nations’ vessels. From our perspective, this could imply:

• A potential shift in cost structure —Even if the strait reopens, crude oil transport costs may rise, and this could feed into chemical raw material prices

• Possible shipping lane realignment —Excluded vessels may need to reroute, potentially creating logistics bottlenecks for apparel supply chains in certain regions

• From short-term volatility to a higher baseline —Higher synthetic raw material prices may persist beyond a short-term spike, potentially becoming the new baseline for the coming quarters

A Few Takeaways

• This does not appear to be an immediate “prices jump tomorrow” scenario —Inventory buffers across the supply chain typically provide some cushion. Today’s quotes often reflect costs from 2–3 months ago.

• But the window may be narrowing —With the strait closed for over a month, mills are drawing down inventory. The window for locking in current pricing may be limited.

• Timing may vary by category

  • Polyester filament (activewear, fast fashion): window perhaps 4–6 weeks

  • Nylon, spandex (functional wear, yoga): window perhaps 4–6 weeks

  • Polyester staple fiber (filling, home textiles): window perhaps 6–8 weeks

II. Which Categories May Be Most Affected?

Generally speaking, the higher the synthetic content, the more direct the potential impact.

Higher-Risk Categories (60%+ Synthetic Content)

Lower-Risk Categories

• 100% cotton — relatively less exposed, though synthetic trims (thread, elastic, zippers) still play a role

• Wool, cashmere, silk — not directly affected by petrochemical price movements

• Natural fiber blends — risk depends on the proportion of synthetic content

No category is completely immune. Even a cotton T-shirt relies on synthetic sewing thread and elastic.

III. A Possible Ripple Effect: What Rising Polyester Prices Could Mean for Natural Fibers

If synthetic fiber prices—particularly polyester and nylon—rise significantly, one potential consequence is that some demand may shift toward natural fibers. The prospect of sustained higher synthetic costs due to elevated transit fees could reinforce this trend.

Why Might This Happen?

• Polyester and cotton are substitutes in many basic categories (T-shirts, shirts, sweatpants, underwear)

• When polyester prices rise sufficiently, brands may adjust fabric compositions to increase the proportion of cotton, linen, viscose, or other natural/recycled fibers

• Startups and cost-sensitive buyers in particular may consider shifting away from synthetics to avoid volatility

What Could This Mean?

1. Cotton prices may come under upward pressure

Cotton is the world’s largest-volume natural fiber. If demand shifts toward cotton in a concentrated way, prices may increase. Historically, sharp polyester price increases have sometimes been followed by cotton price increases with a lag of 1–3 months.

2. Supply of certain natural fibers could tighten

Premium categories—long-staple cotton (used in higher-end knits and shirts), Australian wool, Chinese silk—have limited production capacity. A sudden increase in demand could lead to:

• Extended lead times

• Potential quality inconsistency (mills may lower grading standards to meet volume)

• Smaller brands potentially facing lower priority

3. Blended fabrics could face pressure from both sides

Products like polyester-cotton blends and nylon-cotton blends sit in the middle. The synthetic component may rise in price, while the cotton component may also rise if demand increases—meaning blends could absorb cost pressure from both directions.

A Few Considerations

• If you have cotton-heavy orders, you may want to consider locking in raw material or fabric prices sooner rather than later

• If you are considering shifting synthetic orders to cotton, it may be worth factoring in cotton supply stability and price trends

• Long-staple cotton and functional natural fibers may warrant closer attention —these categories have tighter supply and could see sharper volatility

IV. A Few Considerations for Apparel Buyers

The following are offered as observations—not as directives, but as potential points to consider in your own sourcing strategy.

1. Consider Locking in Synthetic Fabric Prices Sooner

If you have orders over the next 3–6 months that involve synthetic fabrics, it may be worth reviewing whether fabric prices are locked. For confirmed orders where fabric prices are not yet fixed, you may want to discuss locking them in with your suppliers.

Why: Fabric mills typically adjust pricing 2–4 weeks after fiber prices rise. The window for locking in current pricing may be limited.

2. Evaluate Fabric Substitution Possibilities

For upcoming developments, you may want to assess whether certain styles could transition to natural fibers or recycled synthetics (rPET). Specification adjustments—such as lower weight, altered weaves, or adjusted blends—might help manage cost increases while preserving handfeel.

A note: Substitutions typically require testing and validation. This may be more suitable for new developments than for already-confirmed orders.

3. Consider Consolidating Orders and Extending Lead Times

Combining smaller orders into larger batches can strengthen negotiation leverage. For basics and core styles, ordering earlier than usual may help lock in current costs.

Why: In a rising raw material environment, placing multiple smaller orders may mean facing price increases repeatedly. Longer order cycles can also give suppliers more flexibility in securing materials.

4. Have Transparent Conversations with Core Suppliers

It may be helpful to better understand your core suppliers’ raw material positions—such as synthetic percentage, purchase timing, and current inventory levels. Establishing price adjustment mechanisms tied to raw material indexes could provide more predictability.

Why: In volatile times, supply stability and visibility may matter as much as unit price.

5. Reassess Supplier Structure

It may be worth considering which of your suppliers have vertical integration—in-house weaving, dyeing, or upstream fiber connections. Vertically integrated suppliers may detect changes earlier and adjust more flexibly.

Why: During periods of volatility, vertical integration can offer greater supply stability.

V. A Longer-Term View: Sourcing Logic May Be Evolving

The traditional sourcing model—cost first, JIT inventory, global division of labor—was built on an assumption of stable global conditions. The current environment may be prompting a shift in priorities:

• Safety and certainty —delivery reliability may carry more weight than unit price alone

• Resilience —a supplier’s ability to navigate volatility may become a more significant consideration

• Partnership —deeper, more collaborative relationships may offer advantages over purely transactional arrangements

From our perspective, the most important question may not be “who is the cheapest supplier right now,” but rather “which suppliers are best equipped to navigate volatility and maintain stability over time.”

Final Thoughts

The Strait of Hormuz closure has now entered its 32nd day. Recent reports suggest the strait may eventually reopen under a “high transit fee, selective access” model—which could mean that higher synthetic raw material prices persist beyond a short-term shock.

We do not believe this is an immediate “prices jump tomorrow” scenario—inventory buffers across the supply chain typically provide a window. However, the orders locked in today may represent some of the most cost-effective opportunities in the coming months if elevated transit fees become a lasting mechanism.

Estimated windows by category (based on typical supply chain timing):

• Polyester filament (activewear, fast fashion): approximately 4–6 weeks

• Nylon, spandex (functional wear): approximately 4–6 weeks

• Polyester staple fiber (filling, home textiles): approximately 6–8 weeks

Please note: These are estimates based on typical supply chain dynamics. Actual timing may vary by supplier, order type, and individual circumstances. The above is offered as observation and reference, not as definitive advice or a guarantee of future outcomes.

If you are evaluating sourcing strategies or would like to discuss raw material trends in more detail, please feel free to reach out. We are happy to share our ongoing observations.

Appendix: Quick Q&A

This article is based on market information available as of March 31, 2026. It reflects our observations and is offered for informational purposes only—not as financial or purchasing advice. Buyers are encouraged to conduct their own due diligence and consult with their own advisors. Supply chain conditions remain dynamic; we recommend maintaining close communication with core suppliers.

Tags: #SupplyChainInsights #StraitOfHormuz #CostManagement #ApparelSourcing #BuyerConsiderations

Author:  Umi Apparel Supply Chain Analysis Team
If you have questions or would like to discuss further, please feel free to reach out. Thank you