* Fallout Prevention: Eyeshadow (especially shimmery or loose pigments) can create fallout, tiny particles that land on your face. If you've already applied eyeliner, the fallout can smudge or dirty the clean line, requiring you to clean it up and reapply.
* Better Blending: If you plan on blending your eyeshadow close to your lash line or using darker eyeshadows to create a smoky effect near your eyeliner, it's much easier to do this *before* the eyeliner is applied. You can easily blend the shadow into the desired shape without worrying about disturbing a perfectly drawn liner.
* Eyeliner as a Guide: Some people use eyeshadow as a guide for their eyeliner, creating a base shape with the shadow that they can then trace over with the liner. This is less common, but some find it helpful.
However, there are some situations where applying eyeliner first might make sense:
* Tightlining: If you are tightlining (applying eyeliner to the upper waterline), it's often easier to do this before applying eyeshadow. This prevents eyeshadow particles from getting into your eyes and ensures a clean application.
* Very Simple Looks: If you're only wearing a light wash of color on your lids and a very basic eyeliner look, the order might not matter as much.
* Personal Preference: Ultimately, makeup application is about what works best for you! If you find that applying eyeliner first gives you better results, there's no rule that says you can't do it that way.
In summary, while most people apply eyeshadow first, there are exceptions depending on the specific look and personal preference. The general reason why eyeshadow is applied first is to avoid messing up your eyeliner with fallout and ensure easy blending.