If you are unfamiliar with self-inflating sleeping pads, have a look at that page to familiarize yourself.
Self-inflating air mattresses are priced between $30 and $150 depending on size, thickness, and quality. Due to the thicker shells and foam core, they tend to be more expensive than inflatable air mattresses.
The mattresses come in a variety of widths from 20" to 36", and a few lengths from 72" to 78". Inflatable air mattresses, on the other hand, come in the standard bed sizes (twin, full, queen, etc).
Self-inflating sleeping pads do not need to be as wide as inflatable air mattresses because there is no fear of rolling out of bed. Sleeping bags and a tent's smaller quarters also work to constrain movement while sleeping.
The fitting room
For leisure camping, the pads should be at least as wide as the shoulders, but you will sleep more comfortably if, when lying on it, the pad extends out a few inches from each shoulder. This will allow you to shift less when sleeping on the pad.
The 20-inch-wide pads should be adequate for children and a few adults. This width is also marketed towards women, who have narrower shoulders than men.
As the height of the camper approaches 6 feet, the common 25" width should be more comfortable and still conserve floor space. Widths in the 30" range will take care of the large and tall crowd.
There are 30" to 36" widths for campers who prefer a lot of sleeping space and have enough floor space in the tent. A 36" self-inflating sleeping pad will feel like a double bed when lying in a sleeping bag on one.
The pad should be at least as long as you are tall. Unless you spend a lot of time sleeping on your stomach, excess length is less important than enough width. 2" of extra length should be enough.
If possible, lie on the pad in the store before purchasing it. Lie on your back and on your side. For trying out sleeping pads and bags, some camping stores have a long bench that you can lie on. This will give you some idea of how the pad performs on hard ground.
Also be aware that you may need extra thickness to cushion against uneven ground.
Most leisure tent campers use rectangular sleeping bags and, instead of turning with the bag, tend to turn inside the bag. Look for a self-inflating sleeping pad with a top surface that will keep the bag from sliding on the pad fabric.
Many leisure campers start with a less-expensive, inflatable air mattress and later move up to a more expensive self-inflating pad.
The pads, in a variety of narrower widths, are more tent-friendly.
Quality
Quality pads have heavy shells that resist wear, punctures, and leaks.
They also have high-quality foam that lasts for years without mildewing or breaking down. Quality foam is also more likely to regain its original shape after long periods of compression.
The original self-inflating sleeping pad was made by Thermorest, but there are currently several manufacturers of quality, self-inflating air mattresses.
Quality, self-inflating air mattresses are often covered by a multi-year factory warranty allowing the pad to be returned to the manufacturer for repair or replacement. This warranty may extend for the life of the pad.
The warranty will ensure that you are able to maintain and enjoy an airtight pad for many years.
Inexpensive, poorly-constructed, self-inflating mattresses have a high failure rate. Because of the failure rate, better camping stores won't carry them.
Inspecting a new mattress
Try to purchase a self-inflating sleeping pad at least two days before camping, in order to allow enough time for inspection and to allow the pad to fully inflate if it has been stored in a rolled, compressed state on a store shelf.
Upon arriving home, unfasten the straps, leave the valve (tightly) closed, and see if the pad starts to self inflate due to a leak—see self-inflating mattress repair. In the unlikely chance it does leak, you can immediately return it to the store for a replacement or refund, instead of having to ship it to the manufacturer.
The next day, if the self-inflating pad is airtight, then open the valve and give it a full day to completely self inflate--especially if the foam core is thick. Inspect it for any obvious defects.
Then lie on it in various positions to make sure it is comfortable. Take it outside to test if you want. If it is not comfortable, you should be able to return it or exchange it for a more comfortable mattress.
If you are satisfied with it, store it fully inflated with the valve open until you are ready to camp.
Decompression
If you've just purchased a self-inflating air mattress and are allowing it to self inflate for the first time, don't expect to see it suddenly spring to life. This is especially true of an inexpensive mattress. The foam may have been compressed for months in a warehouse.
Better-quality foam should show signs of returning to its original shape after a few minutes, but may still take a few hours to regain most of its original shape, and should be stored with the valve open to allow it to completely regain its shape.
Low-quality foam pads should be allowed 24 hours to expand. If a low-quality pad has been compressed too long, it's possible that the foam has been crushed and will never regain its full original size.
Check your pad after 48 hours. The foam should be completely expanded and match the thickness listed in the product literature. If it doesn't, take the pad back for replacement or refund; the foam has probably been crushed.
Conclusion
A self-inflating sleeping pad is a tent-friendly sleeping cushion. It is very camper friendly, as well. It is available in a wide variety of sizes, is easy to set up, and requires a minimum of maintenance