I don't know of a any "1 step-self-weeding" paper for darks. I've heard of the IMAGE CLIP for darks, it could be the closest to what you're looking for. Good luck on your search, and hope you'll share with us your findings.
There's a few out there now, personally i've been giving Wow 7.1 by 'The Magic Touch' a good go lately with durable and strong results. Its quite a complex procedure and you'll want a good heat press. I've also see EZ Trans Image Clip paper but have not tried it, its seems like a simpler process (only 2 steps instead of 3) but couldn't say if it was as durable or as strong at blocking out the dark colour of the garment. Another new product out this year is 'Modern Trans Free Style' Which is similar again but i can't confirm if it is self weeding paper for dark as well as light coloured garments. The problem is there is no why of getting hold of sample packs as the transfer papers dont come cheap. Anyway good luck and hope you find something that works for you.
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