The Serial Seal™ is one size: 0.75" x 1.77". The things you put it on run from a 2 mil sleeve to a 15" storage box. The question is never whether it sticks, but which layer deserves adhesive at all, and whether you wrap an edge or lay it flat.
This page is the index. Every format below has its own post with the full arithmetic. The seal does not change between them, so the run size is just a number you type on the builder.
The one number that decides everything
Fold a seal over an edge and the edge itself eats part of the length. Per-face landing is:
(1.77 - T) / 2
where T is the thickness of the edge you are wrapping. On a penny sleeve T is about 0.004" and you get 0.883" per face. On a 360pt top loader T is 0.391" and you get 0.690". The "0.885 on each side" figure people quote is the zero-thickness upper bound, and on a thick holder it overstates your grip by more than 20%.
There is a floor, and it is ours rather than a spec: in our own handling, a fold gets unreliable somewhere under roughly 0.55 to 0.58 inches of landing per face, and the corners start lifting. Treat it as bench experience, not a measurement, and test one seal on your own holder before committing a run. Every single-card holder in the table below clears it. Stacks are what run it down.
Fold or single
Fold to bridge a clean edge or a welded seam. Single when the joint is a step rather than an edge — a lid over a box, a flap over a body — or when you only want a numbered mark on a flat face. Both styles come in portrait and landscape.
| Format | Style | Where it goes | Landing |
|---|---|---|---|
| Penny sleeve | neither | Do not. Seal the top loader instead | — |
| Top loader, 3" x 4", any point size | FOLD | Open 3" top edge, about 0.6" off center | 0.854" at 20pt, 0.690" at 360pt |
| Semi-rigid card saver | FOLD | Long side edge, never across the flared lip | about 0.86" |
| One-touch magnetic acrylic | FOLD | Any edge mid-span, clear of a magnet | 0.785" at 35pt, 0.585" at 360pt |
| Graded slab | FOLD | Bottom edge, never the top | measure T, then (1.77 - T) / 2
|
| Team bag / resealable bag | SINGLE | Across the flap's free edge, back face | 0.885" either side of the step |
| Sealed wax (box, pack, blaster) | neither | Not on the wax. On an outer acrylic case | — |
| ETB acrylic display case | SINGLE | Back panel, across the lid line | 0.885" either side |
| Break stack, banded or bagged | FOLD | Across the 3" edge, crossing the band | 0.73" over five standard holders |
| Storage box, 100 to 3200 count | SINGLE | Across the lid line, on two opposite faces | 0.885" lid, 0.885" base |
| Bubble mailer or shipping box | SINGLE | Flap's free edge, or the center flap seam | 0.885" either side |
The SINGLE rows land 0.885" on each side of the joint because a flat seal has no edge thickness to lose. Fold rows always cost you T.
The formats
Top loaders
Rigid PVC, flat, disposable, and the card never touches adhesive. One seal covers 20pt through 360pt — the exterior never changes size. The trap is the thumb notch at top center: a centered fold bridges thin air and dimples. See how to seal a top loader.
Penny sleeves
The film is roughly 2 mil polypropylene, weaker than the adhesive on it, so it gives before the adhesive does — against the card face. Sleeve the card, drop it in a top loader, seal that. Reasoning in how to seal a penny sleeve.
Semi-rigid card savers
The flared 1/2" lip springs open by design, so a seal laid across it tents and self-peels. Fold over a long side edge. Anything heading out for grading should go bare; follow the grader's current intake instructions, not ours. See how to seal a semi-rigid card saver.
One-touch magnetic holders
The parting line runs the whole perimeter, so a fold on any edge crosses it. Acrylic is the catch: aggressive adhesives can craze it permanently, and the damage lands right over the card image. Details in how to seal a one-touch magnetic holder.
Graded slabs
The grade label, cert number and barcode sit at the top of the front face. A top-edge fold lands straight down on them, and covering the barcode makes the slab harder to check when you are selling it sight-unseen. Bottom edge, and measure T yourself, because shells differ by brand. Figures in how to seal a graded slab.
Team bags
Polypropylene is slick, and mild adhesives release from it cleanly, so read how to seal a team bag before deciding the bag is the layer worth numbering. On a 1" flap a single lands 0.885" of seal across the step.
Sealed wax
Never put adhesive on sealed wax — not the film, not the box, not a pack. "Factory sealed" means nothing was applied after the factory. It also fails mechanically: shrink film slides freely over the box. Case the wax and seal the case. Full argument in how to seal sealed wax boxes and packs.
ETB acrylic cases
The case is third-party and comes off the shelf without the wax being handled, so it takes the adhesive the box cannot. Single across the lid line on the back panel; the front face is why you bought a clear box. On a sliding lid, fold a back corner instead so a wing crosses the joint. Never wrap the top edge of a capped lid: both halves land on the lid. See how to seal an ETB acrylic protector.
Break stacks
Same footprint, but height is the variable. Five standard top loaders is 0.31" of edge and leaves 0.73" per face; five 108pt is 1.02" and leaves 0.375". Past about 0.6" of stack, bag the bundle and use a single. See how to seal a break stack.
Storage boxes and show inventory
A telescoping lid sealed on one side lifts freely from the other, hence two seals. On a 3"-tall box, 1.77" covers 59% of the height. Corrugated tears its own liner, so a sealed box is finished cosmetically and not going back into rotation. Workflow in how to serialize storage boxes and show inventory.
Mailers and shipping boxes
Poly-faced mailers release most adhesives intact; kraft and corrugated tear their own liner. Either way the seal only carries the number; the packaging does not change that. Keep it off the carrier label and off outer edges where a sorter can catch it. See how to seal a shipping package.
Eleven formats and one seal size between them is why the builder asks you for only two things: which artwork, and how many.
Step by step
- Pick the layer you are sealing. Almost always the holder or the outer package, never the collectible.
- Measure T and run
(1.77 - T) / 2. Near the floor above, use a single on a flat joint instead of a fold. - Test one seal on a spare holder of the same material. Acrylic and thin films are the ones that surprise you.
- Clean and dry the landing area. Adhesive over dust or residue is how a seal arrives half-lifted, which looks sloppy and costs you a re-seal.
- Place it, then burnish. On a fold, set the first face before working the second so the wrap sits tight to the edge.
- On telescoping lids and one-touch holders, add the second seal opposite.
- Photograph the sealed item with the number legible, note the date, and log the serial against the order.
How many do you need
Across those formats the count is a short sum rather than one multiplication. Most items take one seal. Two do not: a telescoping storage box needs one on each opposite face, and a one-touch holder is often worth a second on the opposite edge.
seals per week = single-seal items in a normal week + (lidded boxes that week x 2)
Run that on last week rather than on a guess, then pick a horizon — thirteen weeks for a quarter, fifty-two for a year. Six sealed items a day, five days a week, is 30 a week: 390 for the quarter, 1,560 for the year.
60 Serial Seal™ minimum · From $30.00 · As low as $0.30 each in bulk.
Seals come in packs of twelve at $6.00 a pack list, with a 60-seal minimum, and the per-seal rate falls as the run gets longer. Seals are ordered in twelves, so that 390-seal quarter rounds up to 396 — past the 120 rung, 45 cents each, $178.20. A 1,584-seal year clears the 1,200 rung at 36 cents each, $570.24. One tier applies per order, automatically at checkout, so the year bought in one go beats twelve monthly orders of 132 seals, which pay 45 cents each and come to $712.80. No setup, die, or design fees. Commercial license and copyright included.
Still deciding which layer to seal? A starter run answers it: 60 for $30.00, 50c each, is the minimum order and is enough to try a fold on a top loader, a fold on a slab and a single on a mailer.
What this does and does not do
On every format on this page a seal can be peeled off and a different one put on in its place. That is true of every adhesive seal ever made, ours included. The stock is thin holographic vinyl on permanent adhesive, so plan the placement before you commit: it will not come off in one piece.
What it does is carry a number. You chose the artwork, we printed the sequence, and no two seals in your order share a number. The routine is then the same across all eleven formats: one number per item, one row per number, one photo tying them together. The seal is not the evidence. Your record is.
Some layouts carry a "VOID IF DAMAGED" line; it is a notice rather than a mechanism, and the FAQ covers it. A seal does not prove a card is real, does not prove a slab was never cracked, and does not authenticate anything. Disputes are decided by whoever runs the platform you sold on, under their rules.
Common mistakes
- Folding dead center on a top loader. The thumb notch is there. Offset about 0.6" and you still have 0.4" to the side weld.
- Sealing the top edge of a graded slab. That is where the label and barcode live. Bottom edge.
- Wrapping a thick stack. Eight 108pt top loaders is 1.63" of edge and leaves 0.07" per face. There is nothing there to hold.
- One seal on a telescoping lid. Sealed on one side, it lifts from the other.
- Adhesive on the collectible. Not on a card, not on sealed wax, not on any surface whose value depends on being unmarked.
- Applying the number and never writing it down. The photo and the log entry are the entire point.
Questions people ask
I ship five different formats. Do I need five different Serial Seals™?
No. One size — 0.75" x 1.77" — covers everything in the table. What changes is fold versus single, and which face it lands on.
There are three layers here: sleeve, holder, mailer. Which one gets the number?
The one you want the photograph of. A holder seal survives the mailer being opened; a mailer seal only tells you about the outer package. Doing both is fine, with the same serial or with two. Never the sleeve, and never the card.
Why not just buy generic void stickers off a roll?
If a number on silver stock is all you want, that works and it is cheaper. What it does not carry is your artwork, your prefix or your starting number, and it is the same sticker everyone else is using. Branded seals versus generic void stickers puts the two side by side, including what neither of them does.
How many Serial Seals™ should I order?
Count sealed items, not cards, and add a second seal for every lidded box. The sum is in "How many do you need" above, along with what each horizon costs.
What you are buying is a run of holographic vinyl seals, 0.75" x 1.77", numbered in sequence, no two the same. The minimum order is 60 for $30.00, 50c each, and the rate steps down with volume to 30c each at 4,200, where it holds; runs past 10,008 are quoted. Read the post for the format you ship most, then take a gallery design to the builder, or bring your own artwork through upload your own logo.
Serial Seal is an independent printer. We are not affiliated with, endorsed by or sponsored by PSA, Beckett, CGC, SGC, Ultra Pro, BCW, eBay, Whatnot, TCGplayer or any card manufacturer. Brand names are used only to describe the products they make. Nothing here is legal advice.
Read next: Custom toploader seals · One-touch and magnetic holder seals · Seals for graded slabs · Custom seals for card breakers · Card shops · Collectors