Methodology

Which sources we trust, in order

Sources are not all worth the same, and the ranking only really matters when two of them disagree.

• Best: the company that made it. Sleeve and holder dimensions come from the manufacturer's own product listing. Tournament rules come from the game publisher's official rulebook. Submission requirements come from the grading company. Measurements only ever come from here.
• Also good: archives and conservation bodies. National archives, national libraries and conservation centres, for anything about materials, humidity, light and long-term damage. They have nothing to sell collectors, which makes them the right people to ask about which plastics are safe.
• Weaker, and flagged when we use it. Some manufacturers and institutions block automated access to their own guidance, or publish it only as a PDF. Where a claim rests on a store listing or a published summary rather than the full document, we say so rather than pretending the sourcing is stronger than it is.
• Not a source at all. Hobby blogs, forum consensus, retailer copy that names no manufacturer, and anything we merely remember reading. None of these can be the origin of a fact on this site, no matter how often it gets repeated.

When two sources disagree

We go with whichever source ranks higher above, and then we tell you about the disagreement on the page itself. If you have read the opposite somewhere else, you should know why we are saying something different.

The clearest example is sleeve sizing for Japanese Pokémon cards. Plenty of hobby sites will tell you Japanese cards need Japanese-size sleeves. But the sleeve manufacturers list Pokémon under standard size with no mention of language, and their Japanese-size lines name only Yu-Gi-Oh! and Cardfight!! Vanguard. We follow the manufacturers, and we explain the clash on the Pokémon sleeves page instead of letting you find it the hard way.

When we can’t verify something

We cut it. This costs us more content than any other rule here, and we would rather have a shorter page than a confident-sounding sentence nobody can check.

One example: we had written a capacity figure for a Dragon Shield binder, taken from a search result rather than the product page. When we went to the product page to confirm the number, it wasn’t there. So the figure came out, rather than staying up with a “roughly” in front of it. Hedged numbers get quoted elsewhere as facts.

Where something is genuinely uncertain but still worth saying, we say it as an uncertainty in the text. We don’t promote it to a specification, and it never goes in a comparison table, because a table makes everything in it look precise.

Where we get things wrong

We fix them, and we keep a note of the fix so the same mistake can’t creep back in during a rewrite. Guides carry the date they were last updated.

A real one: whether D-ring binders damage cards less than round-ring binders is repeated constantly in the hobby, and we originally cut it because we couldn’t find anyone authoritative saying it. That was the wrong call. Avery, which actually manufactures binders, publishes guidance for card binders saying that round rings “can create a curve that can bend your cards”. So the claim went back in, with the source attached, on the binders page and in the glossary. Being strict about sourcing is supposed to stop us publishing things that aren’t true, not stop us publishing things that are.

Things we can’t do

Some sources we can’t read in full. A few grading companies and conservation institutions block automated access to their own guidance, so a handful of claims here rest on those organisations’ store listings and published summaries instead of the complete document. That is weaker, and we’d rather say so than let it pass.

Manufacturer dimensions are nominal. Sleeves and holders vary by around a millimetre between production runs and between brands. A figure quoted to the millimetre tells you what the spec sheet says, not what the item in your hand measures.

We don’t test anything in a lab. This site reports what the companies and institutions responsible for these materials publish. There are no accelerated ageing trials behind any of it, and we won’t pretend otherwise.