Over the sliding glass doors in my apt, there is a half moon window running the full length of the doors. I have SE exposure and no outside overhang or such so during the summer my apt can get quite hot. During the summer I put blackout curtain backing strung on a PVC pipe up in that window. Once fall hits and our days get shorter and cooler I take it down until the next spring. My last "sun shade" finally disintegrated. I bought new blackout material/backing and a friend sewed it so I could mount it on the pipe again. I was thinking of trying to either use some sort of paint or ink to put a simple pattern on the side which will be facing into my apt to make it a little less boring.

Any recommendations for a paint or ink that would be good for such a task without flaking off and making a mess?