My friend Bud recently texted me with a baffling problem. Literally, he was baffled by the lousy baffling in several down comforters he’d purchased.

Bud is 80, a widower and skinny. He gets cold at night. So, as winter approaches, he wants a good down comforter. He likes to get cozy while watching TV and eating, so the white ones aren’t practical. He bought four colored down comforters online at a retailer we’ll call Company C, then returned all four because 30 percent of the sewn-in squares meant to keep the puffy down in place had no fill.

Who knew down bedding was such a shifty business?

He ordered two more from Company L. Same problem. Dead spots. He returned them. Determined to figure out what was going on, Bud (a retired attorney who specialized in product liability) called Company L’s comforter manufacturer.

The woman he spoke to blew some fluff up his shorts about “sewn-in” vs “blown-in” down, claiming sewn-in was better, because the blown-in variety used openings in each compartment to accommodate tube-like blowers, and those openings later became escape hatches for down. She insisted the comforters Bud bought had “the preferred” sewn-in down. So why did they still have empty pockets?

“She was wrong,” Bud said.

I text Bud back. “Instead of a comforter, why don’t you get a well-made white down insert and a colored duvet cover that you can remove and wash?” For those who need a refresh, a comforter is one piece; a duvet has two, an outer cover and an insert.

“You may be better at stuffing the down part into the duvet cover than I,” he responds.

He’s right. The task can feel like arm wrestling an octopus.

Now curious, I set out to get the lowdown on down, and to find out why some comforters and duvet inserts have flat spots. Neither Company C nor Company L returned my call. So I called Missy Tannen, founder of Boll & Branch, a leading luxury linen line. Tannen is the only person I know who is fussier about bedding than I am. The reason she started her company 10 years ago was because she couldn’t find sheets she liked.

When customers kept asking what pillows or duvet inserts she recommended, Tannen added down inserts, comforters and pillows to her line. But first she took a deep dive into down to figure out what made a great product. Here’s what she shared:

Down is that light fluffy foof found beneath the feathers of ducks and geese. Down keeps the birds warm and regulates their temperature — and does the same for us in bedding. Down clusters are three-dimensional spirals. (Feathers are flat, provide no loft and poke through fabric.)

For premium comfort, Tannen said, you want your duvet to be 100 percent goose or duck down, no feathers. Read the label and feel the product. If it feels or sounds crunchy, it has feathers. Look for ethical sourcing, too. An IDFL Down Standard symbol means the product meets international requirements for responsible, traceable sourcing.

Industry insiders measure down by its fill power, which ranges from 500 to 800. The higher the number, the warmer and loftier the covers. Down inserts and comforters come in light, medium and heavier weights. Your preference will vary depending on where you live, whether you sleep hot or cool and whether you change your bedding with the season. For those prone to allergies, synthetic down alternatives are also available, and they’re getting better.

The fabric that covers the fill also matters. It needs to be tight enough to keep the fill fibers in and open enough to let air through. Look for 100 percent cotton or linen and avoid any synthetic or chemically coated fabric.

Down inserts and comforters keep their down in place with sewn-in square compartments or baffle boxes. Sewn-in squares connect the top and bottom layers directly. Each square is filled with down, but because no fill exists at the seams and down fill peaks at the center of the squares, heat distribution is uneven.

Higher-end down comforters and inserts have baffle boxes, a grid-like layer of one-inch-high fabric walls that slip between and are stitched to top and bottom layers, forming square chambers. Pressure tubes blow down into each chamber in precise amounts distributing it more evenly, eliminating cold spots.

Tannen suspects the problem with Bud’s various comforters was due to manufacturer error and poor quality control. (Her company puts each item on a lightbox and a scale.)

Bud may pay a premium for baffled bedding, but at least he won’t lose sleep over it.

Marni Jameson is the author of seven books including “Downsizing the Family Home.” Reach her at marni@marnijameson.com.