The thickness of relic baseball cards can vary depending on the material used and the manufacturer, but most cards fall within a fairly narrow thickness range. The average relic card thickness is generally between 0.0075-0.0125 inches or about 2-3 times thicker than a standard baseball card.
The thickness is dictated primarily by the swatch or piece of game-worn memorabilia that is encapsulated within the card. Jersey fabric swatches and pieces of bats tend to be thinner materials, usually resulting in a relic card thickness under 0.010 inches. Thicker swatches cut from pants, socks or other heavier materials may produce a card closer to 0.0125 inches. Manufacturers need to leave enough space inside the protective casing to properly display the relic without it getting damaged or looking crammed and wrinkled.
On Topps flagship relic cards from the past decade, the thickness has consistently held between 0.0100-0.0115 inches. This width allows the fabric swatch to be visible through the front plastic layer without adding too much bulk. Panini and other third-party brands tend to be on the thinner side, around 0.0075-0.0100 inches to mimic the svelte profile of a standard card. Memorabilia cards released in sets like ToppsChrome and Finest are laser cut which produces an even thinner 0.0065-0.0085 inch thickness.
Going back prior to 2010, some older Topps and Upper Deck relics measured a bit thicker in the 0.0125-0.0150 inch range. This was likely due to looser overall quality control and the desire to make the relic portion stand out more prominently inside the protective coating. It could also relate to swatches being slightly larger or packed in more densely during the earlier years of relic card production. So vintage memorabilia cards from the 1990s-2000s may feel a touch heftier between the fingers compared to more modern issues.
The process of encapsulating a memorabilia swatch within a card also impacts its ultimate thickness. Companies that sandwich the relic between two thin plastic shells will produce a thinner finished product versus embedding it inside a single top-loaded plastic layer. Topps usually takes the latter approach for a slightly puffed-out appearance in hand. Manufacturers may additionally employ varying plastic gauge thicknesses and surface treatments that can tweak the end dimensions up or down by a few thousandths of an inch.
Some specialty release outliers outside the standard thickness parameters do occur from time to time. For example, “Bulky Relic” cards produced by Topps have measured up to 0.0200 inches thick due to incorporating larger fabric cutouts. And “Jersey Relic” models with swatches spanning nearly the entire front of the card push close to 0.0300 inches in size. At the opposite end, “laser relic” parallels employing ultrathin holographic foil can come in under 0.0050 inches thick. But generally speaking, most common relic baseball cards range between 0.0075-0.0125 inches in thickness.
While relic card thickness varies somewhat based on specific manufacturing techniques and materials used, most products adhere closely to a width of 0.0100-0.0115 inches. This balanced dimension allows the included memorabilia piece to be prominently featured without adding undesirable bulk. Card companies have largely settled on this medium profile as an ideal standard thickness for maximizing relic visibility and preserving the original baseball card form factor.