I was recently asked a question about what the difference is between eye primers and eyeshadow bases, particularly as I personally tend to use both under my eyeshadows.
If you have read my article "Beginners Guide to Primers" (here is the link if you havn't) www.frivolousbyangel5ace.blogspot.com/2010/11/beginners-guide-to-primers.html you may know a little about the role of primers for the eye. For me, personally, the main reason for uing a primer is staying power. I HATE creases in my eye make up and I hate it when eyeshadows fade and/or smudge. Primers can also really bring out the colours of the eyeshadows, HOWEVER, I do find that the best primers for staying power such as Too Faced Shadow Insurance or Urban Decay Primer Potion, tend to dry fairly clear. This can be a good thing in terms of ensuring the colour of the primer doesnt interfere with the colour of the eyeshadows I am putting on top, but if I want a shade of eyeshadow to really POP and show true to colour with no skintone showing through, I use an eyeshadow base.
The key properties of an eyeshadow base are that, firstly, it is opaque (i.e. once on you can't see the skin underneath it), secondly it is a cream or gel base (i.e. not a powder or a liquid). Bases are either neutral coloured, or, if you are using a particularly vibrant shade of eyeshadow, you can use a base in a colour matching the colour of your eyeshadow.
One of the easiest ways to obtain a base for your eyeshadows is just to get a coloured khol pencil, or even just a plain old black kohl pencil and rub that over the eyelids, blend and then pat your eyeshadow over it. You may have seen me use my black kohl pencil as a base for dark eyeshadow colours, particularly for smokey eye looks. If, for example, you were to use a purple eyeshadow you can just pick up any old cheap purple shade of kohl pencil and use that in the same way. NYX do some AWESOME jumbo eye pencils which are very very good as bases as they are creamy and well pigmented and come in every shade you can imagine. Barry M also do some similar jumbo eye pencils.
Of course, various cosmetic companies do make specific products to be used as eye shadow bases. MAC make Paint Pots which come in various colours. One of my favourite paint pots is Painterley. This is just a neutral cream base, however it contains silicone so it smooths out the eyelid and also sets dry. It is the perfect neutral base for all eyeshadow colours. On its own, it doesn't have the best staying power, but when used over Urban Decay Primer Potion, the combination is amazing. Benefit also do smudgeproof cream shadow bases in lots of lovely colours.
If you really can't afford to get a separate base, just apply your primer and then put a thin wash of any thick concealer you own. This will have a similar effect.
For me personally, I find that as I am Asian and have NC42 skin, eyeshadows, especially the lighter shades, don't show up that well or you can see my skin showing through. Painterley Paint Pot is a light skin tone shade which really helps to show the colours I like to use and as it sets to dry quite quickly it helps my makeup last that much longer. It is a dream product to me and well worth paying that bit extra for a top quality product.
Hope that was useful, if you have any questions, please let me know!
xoxo Angel5ace xoxo