Thanks for trying your best to nudge this through, and thanks to the wee fella you’re chatting to for at least being open to the idea.
For material
Sometimes Narin supplies quills as part of his kits, and he uses a
flexible/rubber resin. He has also used the same material when casting his 1/5 scale dreds. So, Narin himself could point XM at a good caster to advise on mass-production.
For those kits where Narin doesn't supply quills, kit-builders tend to pick from a number of options, the best 2 being various sizes of
porcupine quills (rigid) and a flexible silicon material called
SUGRU, which is rolled into shape and allowed to cure before use.
Due to this requiring mass-production, the flexible/rubber resin would the best way to go for XM - so again - get XM to speak to Narin direct.
For quill placement
I could photoshop quills into the shots you shared, but since this is a Narin sculpt, there are already plenty of examples of his work out there with quills.
If you wanted to see some examples of Joe Dunaway’s work where he has added porcupine quills to dozens of Narin’s predator sculpts – his site is here -
https://www.modelzone.com/mangrasshopper/ (page 1 of 25 pages!) I’m pretty sure you’ll have seen Joe’s work before, but if you haven’t – prepare to have your mind blown.
Narin also posts HIS builds – with both flexible resin AND porcupine quills – on his Facebook page here -
https://www.facebook.com/Narinstudio/ and on his website here -
https://www.narinstudio.com/webMax/mainMax.html
Let us know if I’ve misunderstood your requirements, or if you need anything more.
Ian/Spike.
.