Hi,
What is the best way to create this simple straight lines textures in blender? (just like the top golden part of this product)
Later on, i want to connect it to the displacement socket in order to get the same effect!
I know that it is pretty simple to create it in photoshop but what is the best way to do it procedural in Blender?
best,
Use sin or cos function from math node, then drive the produced wave through colorramp to shape it as you need (how sharp/round are groove bottoms and tops etc).
wow! thats pretty genius! how did you know this right of the bat? 
I am still struggling to understand the node tree though!
When you need regular repeating lines/waves, sine function is the first thing to try 
Definitely spend a lot of time exploring nodes in Blender. They now appear in many different places and can be tremendously useful. Textures, materials, compositing, Cycles of course …
(Because, at the end of the day, “it is a Digital Computer!”) :yes:
