Collectors keep loving slabs. Third-party grading has brought enhanced transparency, liquidity and confidence to the rare coin market. Perhaps in recognition of this, collectors covet rare encapsulations from grading firms, especially Professional Coin Grading Service and Numismatic Guaranty Corp., and these unusual slabs have become collectibles in their own rights.

At a Sept. 18 auction by Great­Collections, the online auctioneer sold a 1946-D Walking Liberty half dollar graded Mint State 65 by NGC for $3,740. For reference, a normal Gem Uncirculated example of this date sells for around $100, nice MS-66 examples can be found easily for $150 and MS-67 examples routinely sell for around $1,000.

What made the brilliant half dollar special was that it was housed in an old “Black Label” NGC holder that was used by NGC only between September and November 1987. The coin’s orientation in the slab is different than what collectors expect today in that the identifying label is placed on the reverse side while the gold NGC logo is on the obverse side.

Connect with Coin World:

Sign up for our free eNewsletter

Like us on Facebook

Follow us on Twitter

The oddness and rarity of these early slabs has made them immensely popular with slab aficionados today. The black holder looked amazing with brilliant silver coins and gold coins. It fared less favorably with many copper and toned coins.

The black holder has proven so popular over time that it was re-released by NGC to celebrate its 25th anniversary through a “Retro Holder” slab that mimics the black core of the original, but includes NGC’s EdgeView prongs and the current standard obverse/reverse label orientation.

Vintage holders sell for thousands online: Two of the most coveted vintage holders were auctioned on GreatCollections.com and eBay for a combined $7,189.99.

PCGS likewise embraced for its 30th anniversary its “Retro ‘Old Green Holder’?” labels that mimic the light green inserts used after the famed “rattler” slabs of its first few years.

Beyond these unusual holders is an entire realm of sample slabs that enjoy an enthusiastic collector base. Joining these is a world of special labels that seems to grow each year as marketers find ways to differentiate seemingly similar products.

What is the investment potential of these special holders? One has to consider if future buyers will find value in them and be willing to pay premiums to support high prices. The NGC black holders from 1987 are undoubtedly rare — estimates suggest that fewer than 200 are known — and they show how far third-party grading as come in the past three decades.

As documentary evidence of a point-in-time in our hobby, their value is undeniable. Their status as a solid investment is one that only time will determine.