I never use Dermablend..
There are alternatives... Theatrical make up is usually cheaper and just as effective as Dermablend.
For example there's cake make up. Or pan cake.
Cake make up came about as a result of the development of Technicolour in the movies. Technicolour was first used in 1916 and its development was patchy until the development of the 'three strip' process using a special camera to record films on red, green and blue negatives in the 1930's.
The biggest technical problem was with make up. Up to the 1930's theatrical make up was mainly greasepaint and powder. Greasepaint was standard because of its abilities to hide facial skin flaws in close ups. However the brighter lighting necessary for the Technicolour filming technique meant that the colours of the surrounding scene were reflected in the sheen of the make up.
The developers of Technicolour were well aware of the problem. A major investor in Technicolour, Jock Whitney, discussed the issue with his racetrack friend, Elizabeth Arden. In 1935 she purchased the DeLong Laboratories and make Up Studio and founded the 'Screen and Stage' division. From this she developed Nuchromatic make up.
However another make up company, Max Factor, took another approach to the problem. They developed the T-D Series of make up. However Max Factor was involved in a road traffic accident in 1936 from which he died in 1938 and his son Frank Factor was put in charge of the development.
The T-D series was first commercially used in the 1937 Technicolour films 'Vogues of 1938' (Walter Wanger Productions) and was highly successful. This new make up was later trademarked as 'Pan Cake' and adopted by all the Hollywood studios. As a result Elizabeth Arden's 'Screen and Stage' division closed down at the end of the 1930's.
Pan Cake became the definition of cake make up. Pan Cake was so successful it financed the entire development of the whole Max Factor range of cosmetics and even today is the model for most make up foundations which are sold.
There are two types of cake make up - dry and moist. Dry cake make up is solid and sold in a tub or 'pan' by companies such as Grimas and Kryolan. You apply dry cake make up with a damp sponge, let it dry, and apply fixative or loose powder to 'set it'.
Dry cake make up covers up blemishes such as beard shadow and is resistant to both heat and water. When applied dry cake make up is much thinner than normal make up and blends in much better with your skin.
The downside to dry cake make up is that you have to have the right amount of moisture in the sponge, use only natural (open cell) type sponges, and develop a technique. For this reason in 1947 Max Factor developed 'Pan Stik', which is still sold today and which is the defining model of all concealers.
Moist cake make up is more like the regular foundation but is generally less oily or greasy than the foundations sold for women. It is applied either by the fingers or a dry latex sponge and also like dry cake make up needs to be 'set' with either loose powder or a fixative.
There is also AA or alcohol activated make up such as the Temptu Pro range. This type of make up is much more fluid than cake make up and is applied by fingers or a sponge. AA make up is both heat and water resistant and requires a fixative or powder. One application of AA make up can last days and it requires a special alcohol solution to remove it.
I use cake make up with loose powder which hides all beard shadow and usually only needs one or two touch ups during the day.
I have also recently discovered Leichner's Camera Clear foundation. At first when I opened the tub and saw the creamy consistency I was sceptical, but have also found it really effective for covering up beard shadow.
You can find any of these cosmetics at at fancy dress or theatrical suppliers (so there's no stigma for those bothered about buying women's cosmetics in a regular store), you can also find these items on E-Bay and Grimas, Kryolan and Leichner have their own websites from which you can order the products.