Straight stitch lines

[bruce johnson]

18 hours ago, ThisIsMyFirstRodeo said:

I lightly case the leather and mark with my wing dividers, and typically run over the groove 2-3x for a nice deeper groove without cutting through, so only my irons (and maybe my awl) actually pierce the grain. 
 

— AZR

This right here. I am not picking on you but if I have to do anything more than once, every pass is a chance for error. It doesn't matter what. Two coats of dye on an edge, multiple hits on a stamp, whatever. Two or three passes with something with no steering like a wing divider - I am not that consistent either. Saddle divider with a wide flat inside surface to follow an edge then yes. 

Now the crabby old guy perspective and not pointed at anyone, just how i learned and was taught. I get this question a lot and here is my answer. The only place I did not groove was stitching into crease lines on wallet interiors with #69 thread. The purpose of a stitch groove is to recess the thread to prevent thread wear and/or add comfort to user in contact areas. They make different styles of groovers and different size grooving tips. You can match the groove width and depth to the thread size. even the amount of pressure you use can control depth and width with some groovers. You don't have to dig a 3x3 ditch for #92 thread and a scratch line for #346 is just a target line for straight stitching and not functional. For the people who say that you weaken the leather, I hear that a lot. The "strength of leather is all in the grain". OK, take that little spindle of leather you grooved off and pull it apart between a two finger grip. If that is the strength you need to keep your work together you have bigger problems. There is essentially no added strength in that little hair of leather. If there was then there would be instructions on how to make projects with it (actually you can make decorative miniature bird nests with it). The strength of the leather is all in the density of the dermis, thickness, and what part of the hide it comes from. That little sliver of epidermis is inconsequential.  I have stickers made up (see below) on all the sewing machines in the shop for my wife and anyone who comes over and borrows some machine time.   

[AlZilla]

2 hours ago, ThisIsMyFirstRodeo said:

“personal” nor a “sale item”, but a gift for a friend that I hope will also give business leads

I wouldn't deliver a flawed product in this case.

[ThisIsMyFirstRodeo]

Thank you for all of your input guys, and Bruce, thank you for your cheat sheet with thread sizing. 
Absolutely not knocking your advice, but thread sizing is rather lost on me. I’ve never even used a sewing machine, and I hand-stitch with almost always .8mm Ritza, though obviously the same principles apply. Not sure right at the moment who mentioned the saddle creaser, but it’s definitely on my list of tools to get (and I know they’re generally pretty cheap).

 In the end, I actually had to rework the strap anyway because I trusted my cuts to be exact, which they weren’t, and I bonded it with another strap wider so I could simply trim to fit properly. It actually allowed me to sandwich a strip of cushy chrome tan, so added bonus on finish features. 
 

Thank you again everyone. I will definitely keep everyone’s advice in mind as I keep working and learning. 
 

Happy holidays to all,

Preston

On 12/18/2025 at 6:52 PM, AlZilla said: