Before our last trip, we bought a Zyliss plastic lettuce knife to possibly take with us. As commited one-baggers, we were only taking cabin luggage. We wondered whether one of these knives would be ok to take with us. We figured that it wouldn't show up really obviously on an xray scanner, but if our bags were manually searched then it would easily be noticed. It was cheap enough that if it was confiscated, we wouldn't be too upset. However, in the end we decided it was best to leave it at home. Didn't want our holiday spoiled just for wanting to take a plastic knife.
I still do wonder though, whether it would be acceptable. We did take plastic picnic cutlery with us. In that, there were of course, knives. What's the difference between a plastic picnic cutlery knife, and one of these? I don't know.
The points for it were that it was reasonably light, and definitely not metal. Despite being plastic, its serrated blade was really quite good at cutting. Before we decided not to take it, I actually prepared a whole meal using it once. (I think it was a mince meal though, and didn't need any raw meat cut in preparation!) The vegies were much more roughly cut than I would normally have, but it did work well enough for vacation cuisine!
I'm still not sure about it, but present it here in case the idea is of use to you.
We are John and Yvette, parents of two young children. We live in Australia and love to travel. We are sharing our kiddie travel tips and articles so that you too can soon be enjoying travel with kids!