Tizer, the soft drink from A.G.Barr, have had a variety of slogans over the decades, & "Get Tizered!" was current in the mid to late 1970s.
This was a mail-away promotion, for which you would receive a variety of gifts: a satin patch — i.e., a sticker — featuring the slogan "I'm Tizered" (which unfortunately we can't show you at the moment), an iron-on tee-shirt transfer, & a Letraset Special Sheet (S52769) featuring an alphabet made up of Tizer characters.
I've flipped the iron-on transfer in Photoshop so you can read it more easily:
Occam's Razor suggests that Letraset would have produced the iron-on & sticker as well as the Special Sheet, but of course we can't tell for absolutely certain. But — why wouldn't they? They had the technology, & it wouldn't be a first!
Picture Credit: The SPLAT Scan Archives
© Tom Vinelott 2023