I use a seam ripper for some 'repairs' but if it is a seam the be torn out I use a 30 - 40 year old (or older) disposable scalpel! My sister is a nurse and used to work in the OR. She gave me several and I still have two left. They work great! Never thought about seam rippers going dull. Who knew? O.k. a lot of you knew and that is why the rest of us are here - to learn. Thanks!