I think everybody already know that Rigged mesh with two alpha layers beside each other are not friends at all. This is the best think i could think of to fix the alpha issue, offering blend/mask button for lashes. Whenever you need to wear eyemakeup you can use the Mask option and change the lashes texture to the texture that was made specially for masking. Wear blend lashes when you don't have eyemakeup on. If u ever click blend and the lashes doesn't respond just detach the head and attach it again that
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