When I first came around to SRP and decided I wanted to get into honing in a serious way I was confused about this. One member even posted against taping the spine as a moral issue. Early on when I went over to forum member and IMO honemiester The Topher's house he taped the spine on my Goldedge before he honed it.

After he was done I asked him if he taped all of the razors that he honed and he said that he taped all that he honed for others. He said that he wasn't going to return a razor to a customer that wasn't cosmetically as nice as when he had received it.... or something the that effect.

I began to tape because I wasn't confident in my ability and I figured if I ended up doing far more laps then necessary and/or used too much pressure I wouldn't put excess wear on the spine. I figured that once I felt confident that I knew my way around a razor hone I could choose whether to tape or not. I have reached that point and I choose to tape. For now anyway although I reserve the right to change my mind.

It is reassuring to me to hear from members with far more knowledge and experience then I have that they find no harm in taping the spine and maybe even some benefits.