newbie What did I do wrong? (leather weight question)

[Deemer]

I'm a novice in leather working. I've made a few simple items out of veg tan scrap here and there and always just picked pieces from my bag that were the right thickness and size.

I find myself with some time on my hands these days and wanted to recreate a simple messenger bag (only a little bit larger than the original) I had made for me a few years ago and think I have the skills to do so now. 

The bag I have measures 2.6mm to 2.8mm thick (measured with digital calipers) at all available edges which plants me well into the 6/7oz range, right? So I order some 6/7 oz leather.

I received the leather, and opened the box and my heart sank a little. It seemed so thick! Remembering that I always think new leather looks thick because it's usually stiff and the edges haven't been beveled yet, I grab my trusty calipers. I found one spot along the edges that measures 2.8mm, but it's 3.0mm to 3.3mm everywhere else, with a couple of spots hitting 3.5mm. This plants it firmly in 7-8oz territory, right? 

Did I measure wrong? I'm quite confident in my ability to measure with calipers, so is there something specific to measuring leather that I missed out on? Did I use the wrong mm to leather thickness scale?

Thanks for any insight!

 

Edited December 24, 2017 by Deemer

[Mark842]

Unfortunately this happens. 5-6 oz from one supplier or tannery rarely is the same thickness from another. Some suppliers vary so much hide to hide from the same tannery I won't use them. About the only think I can tell you is find one supplier you like that is fairly accurate and stick with them. On stuff that I need really accurate I will pay for the hide to be split to exactly what I need.

[Deemer]

Hrmmm. 

 

I was hoping I did something wrong - it's much easier to learn from a mistake than to deal with industry wide issues. Oh well, I'm sure there will be many lessons learned via mistake working with this chunk of too-thick leather - fortunately they sent me 2sq ft more than I ordered!