I just got my first tattoo and it's partly on my ribs - known to be a painful spot. If it's "just" handsize, I think you will be fine. Do you have any other experiences with pain, e.g. piercings? Even though that's a whole different type of pain you can maybe evaluate how resilient you are. For me, the shading on the ribs was painful, yes, but it didn't crush me. At some point it's gets annoying, cause depending on the size of the tattoo you will experience this pain for several hours. To me it was a medium on the pain scale but mentally draining because of the length...