You can get these round (and some square) pinback buttons in a range of sizes, from a self-effacing 1 1/4" to an emphatic 6".
The prices shown are for the 2 1/4" size.
Now, granted: you might rather have a penannular brooch. But unless you're gathering your cloak around you these may be a bit more practical.
They won't leave those huge holes in your clothes, for one.
Of course if you really
a penannular brooch on your shirt - while avoiding the gaping holes problem - you might try
THE CELTIC ART WORKS
> Ars Celtica > Celtic Knotwork Pinback Buttons
Gaelic Angel Button
Knotwork Circle Round Button
Knotwork Labrys Round Button
Knotwork Chaos Star Button
Duotone Celtic Skull & Bones Button
Celtic Skull & Biohazard Button
Celtic Biohazard Round Button
Thor's Hammer Round Button
Odin's Horn Button
Celtic Harp Button (Dark)
Celtic Harp Button
Celtic Knot Button
Celtic Skull & Crossbones Button
Celtic Biohazard Square Button
Silver Pentacle Round Button
Orders for merchandise from 'Ars Celtica' are filled by Zazzle. They're billed and shipped separately from merchandise ordered through the vendors who supply 'Saga Shirts' and my other products.