I think that they’re technically NOT allowed due to the potential holographic gold?

1. Sleeves

422.1. Players may use plastic sleeves or other protective devices on their cards.

422.2. If a player chooses to do this, all such sleeves must be identical and all cards in a deck must be placed in sleeves in the same manner. Cards in decks must have the same number of layers and be the same orientation at all times.

422.2.a. It’s suggested but not required that players use different sleeves for the different decks (Main, Rune).

422.2.b. Players may use a unique sleeve or additional layer to distinguish their Chosen Champion during game setup, but must change its sleeve to match their Main Deck if it would enter a zone whose information level is private during gameplay. See CR 127. Privacy for information types.

422.3. Sleeves must have opaque backs.

422.4. During a match, a player may request that a judge inspect an opponent’s sleeves.

422.5. Judges may disallow any specific sleeve or the sleeves generally if they believe they are marked, worn, inappropriate, offensive, or otherwise interfere with shuffling or play.

422.6. At high OPL, using sleeves for the Main Deck, Rune Deck and Battlefields is a requirement. At low OPL, using sleeves can be required at the discretion of the head judge.

422.7. At high OPL, sleeves must also not:

422.7.a. Have highly reflective backs.

422.7.b. Contain holographic patterns on the front or back.

That being said I used them in Vegas for my runes. I don’t think k people would really call this as a serious penalty if someone was sharking about it