My chef has been complaining that our lettuce has been turning brown and suspects that it's because of my knife. i use a 10inch kiritsuke gyoto by shun the blue steel one. it is pretty heavy which could be the cause but i don't think it is. im looking to get a nakiri or usuba for cutting vegetables at work and was wondering which one would be best for me. i read that usuba's are single bevel and nakiri's are double bevel which is the only difference and im not a pro nor have used a single bevel knife before. i was also wondering why these knives are so short i see them at like 5-6inches usually. any recommendations on the knife as well? im not a huge fan of shun i think they are over priced only reason i got it was because the other knives i was looking at were more expensive or shorter in length then my previous knife. im looking for a comfortable wooden handle don't know much about metal types as well besides that some rust easily and need to be oiled.