Here another photo of my Katana, apologies for it not being better, I don’t really have the means of lighting such a shot. The Hamon or blade pattern is very clear in the right light. This pattern is a result of the application of clay and the cooling process during the forging of the blade. The sword itself dates from Shōwa period, though the exact date I can not confirm. For a more detailed view of the hilt and Suba check the link.