Sembella Geltex: mattress foam still can’t match a good old pillow

A good pillow is essential to healthy sleep. Plenty of people go through a bunch before finding the right one for them. As a result, manufacturers come up with ever-new ideas – like this Geltex pillow, which I’ve been testing over the past few weeks.

How to find the right pillow

First off, there’s no one pillow that’ll help everyone get a good night’s sleep. When choosing a pillow, you need to consider and know a few factors: your sleeping position, the firmness of your mattress, the width of your shoulders. Based on this, you can at least roughly define the height of your pillow and finally decide on a material. Since all this is too complex for just an infobox, I invite you to read my pillow guide

I start by looking at Sembella’s product description. Here’s each point:

A specially shaped pillow

Well, that’s obvious. The dimensions of the Sembella pillow don’t fit any of the current standards. It’s 68 centimetres long, 34 centimetres wide and around eleven centimetres tall. It won’t work with any common pillow cases.

A 100 per cent GELTEX® core

Remember: it’s always best to use capital letters in marketing. They make a word stand out from the uniformity of text. NOPE. Even with a trademark symbol behind it, Geltex isn’t any better or more important than anything else. After all, it’s nothing more than a specific polyurethane foam, combining the properties of open-cell cold foam and elastic gel. And while the «100 per cent» could suggest purity, it actually only means that the core is made from this one material. Lowering production costs. These marketing drones are pretty clever…

Ventilation channels for pleasant sleep

Ooh, now we’re getting fancy. You could also simply call these «ventilation channels» what they are: holes cut into the foam block. They ensure that the centre of the pillow is slightly softer, so your head sinks in more there. However, ventilation is physically restricted since your head is at one end of the tunnel and the other end is on the mattress. More like congested ventilation, then. In any case, I didn’t feel any cooler than with a pillow without ventilation. Even Swiss cheese probably has better aeration than this pillow. Stronger smell, though.

A washable cover

Thank goodness, for once they’re not being obtuse. I can remove the cover of the Geltex pillow and wash it at up to 60 degrees. Pretty important too, since I only have this one cover. I can’t fit anything else on because of the special shape (read above section). When attaching the cover, I notice I can only use it on one side. There’s a zipper on the back. Lying on it would prove pretty uncomfortable. But I don’t think the intended side is ideal either. The cover has a clearly perceptible structure to it. Even the word Geltex (in capitals, of course) is emblazoned. It’s very possible the brand name could imprint on my cheek overnight if I position my head the wrong way. No thank you.

There’s a thin layer of cellulose between the Geltex core and the cover. It’s pretty low-quality, there’s already loose thread on either side.

How did I sleep on the Geltex pillow?

The shape of this Sembella Geltex pillow kind of reminds me of a bone-shaped dog treat: narrow in the centre, wider at the ends. Here’s why they did this: as a side sleeper, my head lies in the middle, while the wider sides support my neck and shoulders. Broadly, this works quite well for me. However, I find the centre section of the pillow too soft; the ventilation tubes in the foam noticeably reduce stability here.

The pillow has two heights, eight centimetres on one side and 11.5 centimetres on the other. However, height alone says little about whether you’ll be comfortable lying on it. Material strength is another important factor here. And compared to other pillows, Sembella’s Geltex foam tends to be on the softer side and offers little support.

This could also be due to the fact that Geltex was originally a foam developed for mattresses and toppers. It’s found, for example, in mattresses from Schlaraffia. Until recently, like Sembella, it belonged to the Belgian Recticel Group, whose polyurethane foams are used for insulation, noise protection and bedding, among other things. Schlaraffia and Sembella have been part of the Portuguese Aquinos Group since 2022.

However, pillows have slightly different requirements than a mattress. From a business point of view, putting foam you already produce into a pillowcase and selling it may sound convincing.

But I’m not convinced. Even the higher side is too low for me. The pillow cover is too rough in my opinion, and the Geltex lettering on it is completely unnecessary.