Scars on grafted trees

Hello Everyone, I have a simple question for all you tree grafters, no pun intended. I'm of opinion that any and all grafted trees would produce and show a  physically visible healing scar. Am I right?
Thanks

All my grafts have scars, although over time they tend to fade. Some have faded so much that they are hardley visible at all.

I've always seen scars, at least until the tree gets bigger.  My 20 year old trees don't have a scar that I can find anymore.

Ok, Please tell me if you can spot any scars on these trees. These are all 5 years old.

I'm not familiar with those types of trees, but it sure looks like a graft just above the ground on the Saijo.