First of all the t-zone is the area across your nose and down your chin. Think of a lower case "t". Second oiliness or lack of it is judged by the cheeks. If your cheeks develop a shine within a couple of hours after applying makeup then yes you are oily. Shine in the t-zone indicates a normal skin. Dry skins know that they are dry and oily skins know that they are oily. Normal skins tend to think that they are oilier than they are. Check the cheeks to be sure.
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