Transfer tape

[Spitzy]

Just a quick question about something I have seen in you tube vids for transferring dark fabric cameo cut transfers from the paper backing to the shirt without upsetting the design. I think its called transfer tape or transfer sheets, ive been searching around to find some but as I don't really know what I'm looking for its proving difficult. Does anyone know what i'm talking about and if so where I can purchase some
Many thanks
Spitzy