The lowest fill, for sleeping face down
Sleeping face down calls for the lowest hull fill of any position, a pillow flat enough that your head barely rises off the mattress.
In short: Run a standard pillow about half to two-thirds full, keep it under 3 inches high, and take out more hulls on a soft mattress.
The fill, specified
| Item | Specification | Source |
|---|---|---|
| Target height, lying on it | Low pillows of up to 3 inches suit stomach sleepers, and some sleepers use even no pillow at all. Most stomach sleepers prefer low to medium height. | Amerisleep height guide; Sleep Foundation |
| Fill weight for a standard 20 by 26 inch pillow | By one seller's figure a standard-sized pillow will require around 7-9 lbs of buckwheat hulls. For stomach sleepers, one seller advises going as low as 50–65% full. | Hullo; PineTales |
| Hull volume, in litres | 1 litre of hull weighs approx 100g, and a 10kg bag of about 120 litres fills approx 3 standard sized bed pillows. One seller says stomach sleepers may need to remove 2-5 gallons. No seller publishes a litre figure for a face-down fill, so none is given here. | Sovereign Foods; Hullo |
| Polished or unpolished hulls | Either. Polishing changes the sound, not the height. Hull noise decreases as the hulls break in, and after a couple of months the pillow is quieter. | Hullo |
| Pure hull or hull with wool | Pure hull. One published hull-and-wool design gives 4 inches of height with the wool on top, above the target, and is made for side sleepers. | Natural Linens product page |
Why this fill follows from your answers
Lying face down, the head turns to one side and rests almost level with the chest. Any height under it bends the neck backward, and the strain builds over a full night. That is why this answer outweighs every other answer in the quiz. The Amerisleep height guide puts a low pillow for this position at up to 3 inches. One review warns that if the pillow is too thick, it can force the head and neck to rest at an uncomfortable angle.
Height matters even for back sleepers, who need more of it. In a PeerJ study, average pressure on the skull was about 30% higher on a 170 mm pillow than on a 110 mm one. The same paper states that optimal pillow height does not correlate with individual anthropometrical dimensions. A chart gives only a starting point.
Hulls suit this job because they hold whatever shape they are pressed into, including a very flat one. A sleeper can scoop a hollow for the face and leave the edges low. Foam cannot do that. The spinal alignment guide gives the target heights for back and side sleeping too.
What changes it
Of everything you answered, the mattress changes the fill most. One seller's guidance is that the softer the mattress, the lower your pillow needs to be, and a very soft mattress means removing more hulls. On a firm bed the whole gap between face and mattress stays open for the pillow to fill. Start near two-thirds full there. On a soft bed, start near half. For stomach sleepers, PineTales advises going as low as 50–65% full, and Hullo says a stomach sleeper may need to remove 2-5 gallons.
Weight and sound change the feel. Neither changes the target height. By Hullo's figure, a standard pillow takes around 7-9 lbs of hulls, and a half-full one is easier for you to push into shape at night. The weight guide explains why the weight is part of the design. You will probably tune out the crunch, since most people adjust to the sound after a few nights. If you are still unsure, the polished versus unpolished guide covers the quieter option. A wool layer softens the surface under your cheek but adds height of its own. One published hull-and-wool design sits at 4 inches with the wool on top. Check its published height against the target before settling on one.
What to check on your own bed
Lie face down on the pillow the way you normally sleep. Ask someone to look from the side. The head should sit level with the spine, not tipped back. If it tips back, take out a cup of hulls. Try again the next night. Store the spare hulls in a dry, closed bag, as the mould guide explains. Some face-down sleepers keep removing hulls until almost nothing is left under the head. That still counts as a correct fit.