Simply put, an oil-based foundation is one in which the basic component is oil with water suspended in it. A water-based foundation is the opposite. If your skin is slightly oily, we suggest one that is water-based – it won’t add unnecessary oils to the skin surface. The water-based will last longer on your type of skin and will keep its true color. If an oil-based or cream foundation were to be used, it could change color. (The water-based foundation is often powder suspended in water so must be shaken before being used.) If your skin is a combination type, you could try a tinted gel or cream that gives a glow but minimum cover, or choose a light moisturizing liquid foundation (especially in the winter as it helps minimize dehydration.)

Oil-based foundations have added oils or emollients for use on drier skins. Where ingredients are listed, oil will be listed first on oil-based cosmetics and water is first on the water-based. When properly chosen and applied, foundations can improve the texture and appearance of the skin and even out its color. They give either a matte or dewy finish. All bases are best applied with a cosmetic sponge, dampened for sheerer coverage.

Is it necessary to apply moisturizer to the skin before the application of a foundation? It seems too heavy to me to do both.

Just as a foundation is best chosen to suit the skin type, so is a moisturizer best chosen in the same way. Moisturizers come in many forms such as creams, liquids, gels. Each has different proportions of water to oil in the formulations, depending on the type of skin for which it is meant. Generally speaking, oil-based, cream type moisturizers afford the heaviest protection whereas the various liquids offer a wide range of protection from non-oily to emulsion forms containing specialized ingredients to benefit the skin in some way.

If you have an oily skin it is possible that the moisturizer or the foundation, or the combination, is too rich for you. For example, if the moisturizer is the cream type and the foundation is oil-based, it would feel too heavy on this type of skin. Check that both products are suitable for your skin type.

The moisturizer should be applied thinly all over the face and throat (using a separate eye cream), and the foundation is applied over this. A moisturizer that is suited to your skin type prolongs the properties of the foundation and helps to prevent a color change on the skin. The moisturizing emulsion also helps prevent any moisture in the foundation from being absorbed into the skin. This would have the effect of leaving behind unattractive patches of color pigment on the skin. Foundation flows more smoothly onto a moisturized skin. When properly applied, the foundation should last throughout the day without needing to be retouched.

It seems that every winter my toenail separates from one of my toes for no apparent reason. Do you know what could cause this?

The separation of the nail plate from the nail bed can be caused by a traumatic injury, constant pressure on the nail, eg. from tight-fitting boots, or constant banging of the nail either in high-heeled shoes or from running shoes, (during squash or raquetball, for example). Other possible causes include fungus, psoriasis, allergy to a nail product (polish, cuticle remover, polish remover, etc.) and some medications. Fungi may proliferate inside winter footwear. See your doctor or a podiatrist, especially if other symptoms such as ridging or discoloration appear.