Anyone make their own dog harness?

So I was talking to a friend and she was asking me about harnesses, and me, as stupid as can be said. Oh I can make that. Just because I can sew nylon and fleece together does not mean I have the skills to calculate what is required of me to make the right size harness.

So we got his size (this is just an example) say its 23" around his girth, how would I determine what the circumference of the collar and length of the connector (that connects the collar part and the girth together) is?

It should look like this in the end. Clean Run: Walkeez Fleece-lined Harnesses

I am not breaking any CR laws, just making my friend a harness, and having lots of issues trying to figure it out lol. Thats really the only issue I got. the rest of it I pretty much got down pat. I am scared I am going to spend money on materials and then mess it up. I am not making her pay for anything buy materials and shipping so it wouldnt be cool to make it all wrong and then make her pay for more materials to fix it.

Any input would be awesome, I keep looking for stuff, but there is no information on the web.

Depends, what is the length of the dog between those 2 parts? I would take that, then add on some extra inches so it's adjustable

Thats the thing, its going to be on fleece so the collar part wont be adjustable - hence I cant screw it up lol. Its girth (just using it as an example, is say - 23") How do you figure the collar circumference for the harness given based off of that? is what I am trying to figure out.

wait, you need to know the collar circumference? I would just get them to take measurements, don't risk just guessing.

its more complex than that. I am sure there is some special way of taking the girth measurements and making the collar size and everthing else to par to fit with it. If I cant find out what it is, then I will just get the exact measurements, but the way the harness is designed it should work to fit a general collar size for the size of the harness, say my friends dog would measure into size 3, the collar size for the harness should comfortably fit every single dog in the 17"-24" girth size which is size 3. So why did they choose that collar size and connector size is what Im getting at? Sure asking her for a size would just be so much easier, and measuring him myself would be easiest but like I KNOW there is some way that Cleanrun and Agility Vision did their harnesses that way, and for the life of me I NEEED to figure it out. I feel like it would fit much better too if it was the way it should be.

I dunno. I am stubborn.

Ahh yay! I think I figured it out !

Thank you for putting up with me though. I played around with a piece of string on Rush and measured her girth, and I read somewhere about adding 10 inches, and that is for the connectors.

So it goes 23" girth, 23" for collar, plus 10 inches for connectors. If I have that right. I'm going to buy material and play around with the idea of it on my own dog first. I have never even see X-style harnesses before today D:

Not to mention it would mean that you would know for sure that the collar part would fit, and would even be a custom fit. I see that you think you've found the answer - but I'd still measure to be sure since it's not going to adjustable.

Yeah I think I am going to ask her to measure him anyway. Though I first have to figure out how that will be lol. This is confusing the crap out of me. The design is really pretty simple, even the parts that seem hard are going to be easy to sew together, but its like the measurement process makes no sense. Even now that I *think* I have it figured out. I am going to mess around with some safety pins tomorrow and make a 'fake' harness on Rush. I dont know what to tell my friend to measure her dog for. Gotta figure that out.