Screen size
The screen size of the device the case is designed for. This parameter directly determines the dimensions of a compatible tablet or e-reader. A device with a larger diagonal will simply not fit into the case, however, smaller sizes than those indicated in the case specifications are also not recommended — at best, the device will hang inside (which will negate many advantages), and at worst, it will not stay in the case at all .
It should be noted that this parameter is critical if you select a universal cover (see "Compatibility"). If the specifications directly indicate compatibility with the model of your tablet or reader, the screen size is for reference only, because. case by definition is optimized for the dimensions of the respective device.
Compatibility
Compatibility of the cover with a specific tablet or e-book model — or the lack of such specialization, in the case of universal models.
For many popular models of tablets and readers, their own specialized covers are produced. They are much better suited for such devices than universal ones, since they are initially “sharpened” for the specific features of a particular model: the dimensions and shape of the case to the nearest millimetre, the location of controls, connectors, cameras, etc. This is especially true in the case of tablets. And for protective covers (see "Type") this is generally the only possible option.
At the same time, universal covers have a wider scope: in fact, in this case, compatibility is determined only by the screen size (see above). This can be useful, for example, if your family has two devices of the same size, but only one of them is taken on trips: you can buy one bag and use it for the desired gadget.
Material
The material from which the cover is made determines its protective properties and a number of other features. To date, cases for tablets and e-books can be used:
— Textile. This type of materials is quite diverse: it includes both soft thin fabrics, designed more to protect against accidental scratches, and dense materials, comparable in strength to plastic and capable of protecting against fairly strong impacts. Almost all fabrics are pleasant to the touch and look good, especially since almost any colour can be given to this material. However, their cost is quite low. Thanks to all this, the fabric is one of the most common materials for covers today; it is used in covers and bags. Different fabrics have different composition, which should be taken into account when cleaning and/or washing such a cover. Among the shortcomings can be called instability to moisture — most fabrics get wet one way or another. At the same time, water-repellent impregnation can be applied to eliminate this.
— Silicone. Polymeric material based on silicon or organosilicon. The advantages of silicone are elasticity, impermeability and resistance to temperature extremes and ultraviolet radiation, due to which it is well suited for dust and moisture-proof covers (see "Dust and water protection"). Disadvantages — Tendency to stretch and lose elasticity over time. It is used quite rarely, and almost never occurs in e-books.
— Rubber. This material combines low cost,...softness, scratch resistance and good protection of the device inside both from scratches and from shocks and shocks, as well as moisture (rubber is waterproof). In addition, the cost of rubber is quite low. The disadvantages are increased sensitivity to temperature changes and wear. Because of this and a number of other reasons, rubber booties are quite rare.
— Plastic. One of the most popular materials used in tablet cases; in e-books is used much less frequently. The advantages of plastic are low cost, good rigidity, resistance to moisture and temperature changes (both the material itself and the protection it provides to the tablet), as well as a bright appearance — plastic can be given almost any colour. The main drawback is that it tends to crack on impact, but in fact it should be quite a strong blow, which is likely to damage the inside of the tablet as well.
— Skin. A kind of fashion material, designed for those who care not only about the functionality, but also about the stylish appearance of the case — leather goods look very solid. The skin is durable, almost waterproof and resistant to temperature changes. The main disadvantage is the difficulty in maintenance: products made from this material require periodic processing with special means and special conditions for cleaning and drying, otherwise cracks and deformations may occur. In addition, leather is quite expensive.
— Leatherette. An artificial analogue of genuine leather: it is much cheaper, while it may not differ much in appearance. Another advantage of leather substitutes is ease of care — they do not require such care as genuine leather. However, they are also characterized by a number of disadvantages inherent in inexpensive materials: a tendency to scuff, sensitivity to temperature changes, as well as a slightly lower strength than genuine leather. In modern cases, various types of leather substitutes are used, differing in price and characteristics; usually, the quality of such material directly depends on the cost.
— Wool. A soft material that resembles a dense thick fabric in its properties (see above). Wool protects the device well from temperature extremes, and also provides some degree of impact protection due to its thickness and softness. However, due to a number of features, in particular the complexity of processing, this material is very rare in cases for tablets and e-books.
Auto on/off
With this function, the case actually turns into a control device for a tablet or e-book: when the screen is closed, the gadget is automatically put into sleep mode, when opened, it goes into working mode. This eliminates the need for the user to turn the device off/on manually every time, and also provides significant energy savings. This function is found only in specialized cases (see "Compatibility"), and the specialization must be extremely accurate — even similar models from the same manufacturer may not work correctly in such a case.
