This is the single most common complaint we hear, and it is almost always blamed on the wrong thing.

Polyester and oil

Polyester is hydrophobic: it repels water. It is also oleophilic: oil is attracted to it and bonds with it. Those two properties together are exactly wrong for a napkin, whose whole job is to take watery liquid off skin and then be cleaned of whatever else came with it.

So a spun polyester napkin is slow to wet out, and once oil is in it, a normal wash cycle will not lift it the way it would from cotton. That is chemistry, not a failure of your laundry.

Why everybody buys it anyway

Because the alternative costs labour. Polyester comes out of a tumble dryer flat and ready. Cotton comes out creased and has to be pressed, which means equipment, floor space and staff time in a building that has none of the three going spare.

For a high-turnover room with no press, the trade is usually still worth making. It should just be made with the facts in hand.

What actually helps

Move toward cotton. Even a poly-cotton blend at a cotton-rich split releases oil noticeably better than a hundred percent polyester, and you can often get most of the benefit without moving all the way to pure cotton and a full pressing operation.

Wash sooner rather than hotter. Oil that has sat in polyester for two days is far harder to shift than oil that goes into the machine the same evening. That is an operational change and it is free.

What does not help

Raising the wash temperature indefinitely. Past a point you are shortening the life of the napkin and the embroidery without lifting the oil.

Stain-release finishes. They are genuinely useful when new and they deplete with every wash. Treat them as a bonus for the first season rather than as the reason you chose the cloth.

Buying a heavier polyester. Weight is not the variable here. The fibre is.