We recently had painters come in and redo the walls, doors, and even some of the carpet!! And on our Clinic Armour pillow cases.
Anyone who has had the experience of commercial painters understands that even despite all the briefing, they often paint things they shouldn't. My experience is never tell painters you are replacing your carpet. This translates to painters thinking, we don't need drop sheets.
In our most recent experience our painters managed to somehow paint the side of one of the Clinic Armour pillow covers. Hmm.
Initially, I thought this would see us throwing this cover out. Instead, I tested whether paint could be removed from the cover.
The paint was dry and had been left for approximately 48 hours when it was discovered on the pillowcase.
I started with gentle warm soapy water, this removed the majority. I was careful not to rub too hard. To my surprise it came off. This was water-based paint, enamel paint way have required an alcohol based solution so contact us for an approved agent.
You will see all the paint came off the cover. A few pin print specks remained in the fabric zip.
I was careful to clean it slowly. Overall it took 2-3 minutes to get it sorted. 
Overall, I was amazed at how it cleaned up. Whilst we wouldn't recommend exposing the covers to paint it was reassuring how easy it was to remove.
Clinic Armour 1 : Painter 0