Nightmare cushions

If it has a cover inside then you could just cover that with another cover and then put the decorative cover on top- I think.

Many years ago I remember my Grandma making some pillow cases from ticking .
She spent a long time rubbing the fabric with a white wax candle to stop the feathers coming through .

Amazon stock Waterproof Down Feather Proof pillow protectors 18 x 18. Dont know what they are like but mught be worth a try.
The quill points are very painful.

Thinking of changing my new cushions to feather, as the synthetic cushions are rather stiff.
I hate the smell of feather cushions though, that’s the downside of them.

I have all feather cushions, so much better than synthetics but I put them in old pillow cases before putting on the cushion covers.

Use down not feathers. More expensive but no pointy bits.

I rememember as children pulling the pointy feathers out of our army issue pillows. Memories.