The pillow may still be visible when you wake. An edge of the case sits above the mattress, while the rest is wedged between the mattress and headboard.
You pull at the case, but the pillow takes more work to free. Putting it back against the headboard at bedtime leaves the same opening waiting for it.
A spare pillow or body pillow pressed into that space may be enough to block it. There is no reason to replace a cushion that fits snugly and stays there. Having to tuck it back every morning, though, leaves you with another pillow to retrieve.
The bed itself can be responsible for a gap that keeps reopening. A frame that slides away from the wall takes anything resting on the mattress along with it. Filling the space makes more sense after the bed stays where you put it.
A headboard wedge pillow fills the fixed space between the mattress and headboard or wall with foam across the head of the bed. Grip dots underneath help it hold its position. One buyer said they could sleep through the night without pulling their pillow out from behind the mattress.
This wedge is designed for gaps up to 6 inches and comes in widths for twin, full, queen, and king beds. It needs to cover the route your pillow takes. A shorter piece of foam may fill the middle while leaving the side open. The pillow would need very little encouragement to find that opening.
Where Your Sleeping Pillow Rests
The sloping foam can change how your usual sleeping pillow sits. One buyer said theirs rode up overnight and ended at an angle they disliked. Gap width alone cannot tell you how your pillow will sit against the slope.
With the opening covered across the head of the bed, a pillow that shifts backward meets the foam. It remains on the mattress, where you can reach it, instead of ending up behind the bed.
