Yumi lashes are an International brand. I've been trained in both LVL and Yumi and Yumi is better training. LVL training is very good and the marketing tips are excellent. LVL has great brand awareness in the UK so I'm very glad I took on LVL.
I personally prefer the Yumi lift. Yumi lash dye is fabulous I have black lashes and the Yumi tint really works well on me - the only one I've ever found worth the bother:lol: Yumi is very popular with darker lashed ladies and with Asian and other Ethnic clients. If you come from a hot country (as I do) your eyelashes will be naturally straight and even downward pointing to protect your eyes from strong bright sunlight. So a lash lift will need to be very good to work. Yumi does.
If you have Caucasian clients I've found Lash Base products to be fine and the best priced. Their supplier makes private label for Flirties, salon system etc, so why pay more? If you order in products and compare their performance you soon realise that some are identical and just the packaging changes, whilst others have been tweaked and have some unique features.
I buy a mixture of products from different suppliers to give me the best result for my clients.