What is the difference between "Total Light Blocking" and "100% Light Blocking"? Parasol labels you should know

When choosing a parasol, you often see terms like "complete blackout" (kanzen shakou) or "100% light-blocking rate." While they may sound similar, these labels actually reflect the varying philosophies and integrity of different manufacturers.

In this article, we, HEATBLOCK, will explain in detail why we choose to use the expression "uses 100% light-blocking fabric" instead of "complete blackout."

Both refer to "top-class fabric"

Generally, both labels indicate that the product uses high-performance fabric that has achieved a 100% light-blocking rate in JIS standard testing (JIS L 1055 Method A). There is no significant difference between the two in terms of the fabric's intrinsic ability to block light.

Why the difference in terminology? Differences in manufacturer stance

So why are the terms used differently? It comes down to whether the term refers to the "fabric" alone or the "entire product."

We intentionally avoid using the word "complete" (kanzen). There are three main reasons for this:

• Acknowledging the reality of the product
  While the fabric itself blocks 100% of light, a parasol is a three-dimensional product made by sewing multiple parts together. We cannot completely rule out the possibility of light leaking through the needle holes created during sewing, so we avoid the word "complete," which implies perfection without a single exception.

• Adhering to advertising regulations
  Under advertising guidelines such as the Act against Unjustifiable Premiums and Misleading Representations, extreme terms like "complete" or "absolute" are generally prohibited.

• Valuing honesty toward our customers
  We believe in honestly communicating the structural limitations of our products so that customers can make informed choices. This is our approach to manufacturing.

Beyond just blocking light: The HEATBLOCK commitment

HEATBLOCK does more than just "reduce glare." To help block the various effects of sunlight, we disclose the following metrics:

• 100% UV Protection: Thoroughly blocks the ultraviolet rays that cause sunburns and dark spots, protecting the health of your skin.

• Visible Light Blocking: Blocks the light that causes glare at a high level. This makes your field of vision comfortable even under intense sunlight.

• Near-Infrared Blocking: Significantly blocks "near-infrared" rays, which are the primary cause of heat and penetrate deep into the skin. This prevents temperature rises under the umbrella, achieving an overwhelming heat-shielding effect (cooling).

Summary: Understanding the background for smarter parasol choices

Rather than choosing based solely on the appeal of terms like "complete blackout" vs. "100% light-blocking rate," we recommend looking at the following points:

1. Is there solid evidence (test data) for the stated values?

2. Is there information available not just on UV protection, but also on cooling (near-infrared blocking)?

3. Does the manufacturer honestly explain the product's structure?

We at HEATBLOCK will continue to deliver products that protect you reliably from sunlight through accurate information and top-tier functionality.