Sticky white tape to prevent light getting in at edge of blinds and curtains

[johnbuoy]

The slightest amount of light wakes up my son. I've got a black out roller blind and black out lined curtains but a tiny amount of light still gets through at the top and sides. Is there some sticky white tape an inch or two thick that I could stick to the window to prevent this?
Thanks.

[PawWavingCat]

We used strips of velcro, one side stuck on to the window frame, the other side sewn onto the blackout curtain.

[BitchyInnerMonologue]

Second the Velcro - you can get white or black and it works well.