The mattress topper that buys a good mattress more years.

SleepOnLatex sells its own Pure Green topper on Amazon, and the listing is refreshingly short: two inches of natural latex from organically grown rubber trees, certified to the Global Organic Latex Standard, from a Fair for Life certified supply. It comes in soft, medium and firm; medium is the safe choice for most people adding a layer to a firm bed.

Two inches of latex is enough to take the edge off a hard mattress and give a side sleeper's shoulder somewhere to go. Latex stays cooler than memory foam because it does not soften with body heat, and it springs back instantly, so you do not feel stuck in a hollow when you turn over.

Skip it if you want a plush, cloud-like bed; that is the featherbed below. The listing does not describe a cover in detail, so plan on a fitted mattress protector over it.

Wool toppers are not about softness. Woolino's is 1.2 inches of merino wool fill in an organic cotton sateen cover, OEKO-TEX Standard 100 certified. It cushions a little, but what owners notice is the climate: wool absorbs moisture vapor and releases it, so a hot sleeper wakes up less clammy and a cold one stays warmer.

The maker says to machine wash cold on a wool cycle, which is unusual for a topper and a real advantage over latex or foam. It also comes with a cotton canvas bag for storing it out of season.

Skip it if the mattress is too hard. An inch of wool will not change the feel much; the latex picks do that. And expect the wool to compress over the first months, which is normal.

Avocado's topper is GOLS certified organic Dunlop latex under a GOTS certified organic cotton cover, and the listing adds MADE SAFE, eco-INSTITUT, OEKO-TEX, Greenguard Gold and formaldehyde-free certifications. That is the most thoroughly documented topper here, which matters to people buying latex specifically to avoid synthetic foam.

Three inches is enough to change the character of a bed, not just soften its surface. The medium feel gives pressure relief at the hips and shoulders without the sink of a plush layer. A 2 inch version and a plush feel are also sold if you want less.

Skip it if the price of a topper is approaching the price of a new mattress for you; at that point the mattress may be the better buy. It is also heavy, and awkward for one person to put on a bed.

Cuddledown has made down bedding in Maine for decades, and its Traditional Featherbed is made to order there. The fill is 95% feathers and 5% down, certified to the Responsible Down Standard, in a 100% cotton twill shell with a 4 inch side gusset and interior baffle boxes that stop the fill from drifting to the edges.

Feathers give the springy lift; the small share of down adds softness. The result is the deep, sink-in bed people remember from European hotels. The shell is OEKO-TEX Standard 100 certified, and it measures 60 inches wide for a queen.

Skip it if you do not want a daily chore. A featherbed needs shaking out to keep its loft, it needs a cover to keep it clean, and quills can occasionally work through. People who want support rather than softness should buy latex.

Sleep & Beyond is a wool bedding specialist, and the myWoolly Latex is its most elaborate topper. It is 3 inches thick, filled with washable Shropshire wool batting, natural latex noodles and wool puffs, 3,000 grams per square meter in all, and hand tufted with a 5 inch perimeter border and two straps to hold it in place.

The combination is the point. The latex adds bounce and pressure relief; the wool handles moisture and temperature. Owners who want the feel of a latex topper without the rubbery surface, or the climate benefits of wool with real cushioning, end up here.

Skip it if you are simply after a softer bed at a fair price; the Pure Green does that for about a third of the money. Tufted wool also flattens a little over time and does better with regular airing.