Originally Posted by LapLap

Nori. All I can tell you is that there are different kinds with one type that disintegrates when wet (which is great for adding to pasta and stirring into dishes) and the other that is sturdier and more robust which is much handier for spam musubi or temaki etc... What I can’t tell you is how to tell them apart without trying it, especially if relying on English packaging or a product information sticker.
There’s also the “Korean” kind (popular in Japan at breakfast time) which has oils and seasonings. These are much more likely to fall apart than not.
All I can say is, check the ingredients. If there is oil listed, or more ingredients than simply nori or laver, I’d assume it would fall apart easily.

Originally Posted by LapLap

Wasabi - unless you’re able to get yourself the fancy stuff (or grow you own) it’s mostly just standard European style horseradish with colouring. If you can get your hands on powdered “wasabi”, you can mix that with a bit of finely grated daikon (or a peeled salad radish) instead of water to get a slightly more “authentic” texture. Even in Japan, a lot of the cheaper wasabi is just zhuzhed up horseradish.
Even freecia might accept powdered wasabi reconstituted with ground daikon - just don’t disclose what it is! If you add a bit of fresh horseradish too it will be indistinguishable from most store bought brands.