Sunflower Lanyard

There is also an embroidered / woven / fabric iron-on or sew-on badge (to add to comfortable clothing or bag you already own):

"The Sunflower embroidered patch and pin badge are perfect alternatives to the lanyard which can be sewn or ironed onto your jacket, bag or any garment to show you have a disability that is not visible.":

https://hdsunflower.com/uk/embroidered-badge-1.html

Also, they now do a 100% cotton t-shirt (adult and child sizes) with a printed "lanyard":

https://hdsunflower.com/uk/printed-t-shirt-1.html

...plus lots of other accessories too.

I posted about these other items just before your reply :)

The patch comes in a bundle with the pin badge. 

The only reason I didn't mention it is because I find such embroidered patches to be just as intolerable, on single-layer clothing, as I find the lanyard is on the back of my neck.

I can't wear v-neck t-shirts for the same reason (the lower part of the opening feels too uncomfortable against my skin), or tops with heavy-feeling transfers / prints on the back or the front.

I posted about these other items just before your reply :)

The patch comes in a bundle with the pin badge. 

The only reason I didn't mention it is because I find such embroidered patches to be just as intolerable, on single-layer clothing, as I find the lanyard is on the back of my neck.

I can't wear v-neck t-shirts for the same reason (the lower part of the opening feels too uncomfortable against my skin), or tops with heavy-feeling transfers / prints on the back or the front.