I've taken some time to look through the article you've linked, and there are a few issues with it. At best, the article is full of unintentional misinformation. At worst, it is full of intentional misinformation. If you want a more detailed explanation, please continue reading.
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The major issue with the article is it frequently mixes up "metallic" cards with
foil cards. Metallic cards are similar to the image you sent in your initial post--a card made almost entirely of a yellow metal, with additional text or coloring added to make it resemble genuine cards.
Foil cards, on the other hand, are made of layers of paper and foil.
![SWSH35_EN_74.png SWSH35_EN_74.png](https://www.pokebeach.com/forums/data/attachments/14/14468-021c5a94f503b870a40cacbf4f75ac88.jpg)
Revisiting the card you sent a picture of, this is what it should look like, taken directly from the Pokemon website
here. This is a
foil card.
I want to clarify that there have been certain cards printed with completely gold artwork. However, they have always had the genuine logos/artwork on the back of the card, and are not fully made of metal.
Is that to say that metallic (i.e. completely made of metal) cards have no value? Objectively, no. They do, technically speaking, have value. It's a matter of finding someone willing to buy it. However, to a collector/player/game store/etc, they have no value, as they are not genuine cards. To be clear: these metallic cards (like the one pictured in your first post)
are not real cards, and as such,
hold no real value.
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Yes, the site you linked is not correct, as it contains a substantial amount of misinformation. Fully metal cards are not real--they are cards made by entities other than the Pokemon Company, and are, quite frankly, a scam targeted at individuals who don't know any better.
My suggestion to you is that, if you have any questions as to whether a card (or cards) you own is genuine, I would strongly consider reaching out to the Pokemon Company's support team or to a local game store or card shop. They will be better able to tell you for sure whether a card is genuine or not, and, in the case of the latter, tell you if it has any value.
I hope this clarifies things a bit further.
Tl;dr - The article is full of misinformation, and is not correct. Metal cards are not genuine cards.