Where or how do I achieve that thin rawhide for Mexican belt braiding??

[Timmmm]

I have seen a thousand videos of Mexican belt braiding. I have seen them cutting their slack from a hide with small lacing tools so I know it comes from a hide that thin. What hide is it that they use? Do they split the whole hide down to paper thin and then use the lace tools? How do I achieve this paper thin lace?

Edited June 18 by Northmount
Corrected typo in title

[bruce johnson]

They are not splitting a whole hide of anything and then cutting lace. 
Two options

- Start with a thinner hide like horse, calf, or goat. 

- Cut a spiral strip or "soga" and then split that down to the desired thickness. If you cut to final width and then split the string can stretch as you pull to split and you end up with narrower sections.  

[Timmmm]

Thank you