A magical pencil that won't break and you can see the lines

[Handplanesandmore]

a pen

I missed the OP's "durable" part.

Why would one want the marking durable? I try to make light marks so they could be erased easily.

Simon

[Handplanesandmore]

https://www.popularwoodworking.com/woodw...ide-day-1/

"And it leaves a bold mark even if you use little downward pressure."

I usually work with fine and slim lines. I do own a pica dry mech pencil for marking on dark wood.

Simon

[johndi]

Have you tried Pica brand? I just grabbed one at Woodcraft and so far so good.

[Hank Knight]

I use a 2mm lead holder with soft HB or 2B lead. It requires a special, very inexpensive sharpener that puts a fine point on the lead. I use a piece of fine sandpaper to refresh the point until I need to renew it with the sharpener. The 2mm lead is strong and, while it certainly is breakable, it is much sturdier than anything else I've tried. I have 4 or 5 of these that I keep around the shop. There are dozens of makers of these pencils. Amazon carries many of them and you can find them at your local drafting supply house. Here's one of several I use:

https://www.amazon.com/Staedtler-Mechani...WNrPXRydWU=

[Steve Altman]

I use a 2mm lead holder with soft HB or 2B lead. It requires a special, very inexpensive sharpener that puts a fine point on the lead. I use a piece of fine sandpaper to refresh the point until I need to renew it with the sharpener. The 2mm lead is strong and, while it certainly is breakable, it is much sturdier than anything else I've tried. I have 4 or 5 of these that I keep around the shop. There are dozens of makers of these pencils. Amazon carries many of them and you can find them at your local drafting supply house. Here's one of several I use:

https://www.amazon.com/Staedtler-Mechani...WNrPXRydWU=

+1, they're great. There are versions of these where the "button" (the part that you use to advance the lead) has a sharpener in it. You just pull the button off, use it to sharpen, then replace. Also, some (the black ones - Mars technico) have a ring that allows you to specify what kind of lead is in the holder.

[handi]

I find 0.07 lead mechanical pencils fine for layout work on light Woods. 

For dark woods I use white colored pencils.

For precision marking, I use a knife. The knife line can be highlighted with pencil.

[daddo]

Yes, it has its place...one weakness of it is it can't be undone as quickly as a swipe of an eraser.

Simon

 You're making a mark, not a groove. Don't press down hard and what fine line you do have sands off easily.

[AHill]

Don't sharpen to a fine point.
Don't use so much force to lay out a line.
Use a softer lead (e.g. No. 2 or HB).

If you're having problems and everyone else doesn't, it's quite possibly your technique and not a lack of viable pencil technology.

[daddo]

When you become one with the spirit of the wood and no longer need markings, only then have you graduated to the ultimate level of woodworking as a master.

[KyleD]

I just use a #2 pencil on smooth woods along with a silver one for darker woods like walnut. If working with an open grain wood like red oak, a sharp pencil tip tends to crumble. I am like K L McReynolds with this type wood and sharpen a carpenters pencil to a knife edge with all the angle on one side. Then I use it like a striking knife.