Jane Iredale PurePressed Base Foundation REFILL in Warm Sienna is a luxurious mineral foundation designed to provide flawless coverage while nourishing and protecting the skin. Here's a detailed description of the product, including key ingredients and how to use it:

**Product Description:**

- **Formula**: The PurePressed Base Foundation is formulated with micronized minerals, which offer a silky smooth texture that effortlessly blends into the skin. It is free from synthetic chemicals, oil, talc, and fragrance, making it suitable for all skin types, including sensitive skin.

- **Coverage**: This foundation offers buildable coverage, allowing you to achieve a sheer to full coverage depending on your preference. It effectively conceals imperfections such as redness, blemishes, and uneven skin tone, leaving behind a natural-looking finish.

- **Finish**: The Warm Sienna shade is specifically designed for individuals with warm undertones. It imparts a warm, sun-kissed glow to the skin, imparting a healthy radiance without appearing cakey or heavy.

- **SPF Protection**: In addition to providing coverage, Jane Iredale PurePressed Base Foundation also offers broad-spectrum SPF 20 protection, shielding the skin from harmful UVA and UVB rays. However, it's always advisable to apply a dedicated sunscreen underneath if prolonged sun exposure is expected.

**Key Ingredients:**

- **Titanium Dioxide and Zinc Oxide**: These mineral ingredients provide natural, physical sun protection, effectively blocking both UVA and UVB rays without irritating the skin.

- **Iron Oxides**: Iron oxides are responsible for the foundation's pigment. They provide natural-looking color while also offering additional sun protection.

- **Algae Extract**: Algae extract is known for its moisturizing and skin-soothing properties. It helps to hydrate the skin and calm inflammation, making it ideal for those with sensitive or dry skin.

**How to Use:**

1. **Prep the Skin**: Start with a clean and moisturized face. Apply your favorite skincare products, allowing them to fully absorb into the skin before proceeding with makeup application.

2. **Apply Primer (Optional)**: If desired, apply a primer to create a smooth canvas for the foundation and to help extend its wear time.

3. **Pick up Product**: Using a dense, kabuki-style brush, swirl the brush into the PurePressed Base Foundation. Tap off any excess product to avoid applying too much at once.

4. **Buff into Skin**: Starting from the center of your face, gently buff the foundation onto the skin using circular motions. Continue blending outward until you achieve your desired level of coverage. For areas that need extra coverage, such as blemishes or redness, you can apply additional layers as needed.

5. **Set with Setting Spray or Powder (Optional)**: To further extend the longevity of your makeup, you can set the foundation with a setting spray or a light dusting of translucent setting powder.

6. **Finish**: Once you're satisfied with the coverage and finish, continue with the rest of your makeup routine, if desired, or leave it as is for a natural look.

Overall, Jane Iredale PurePressed Base Foundation REFILL in Warm Sienna is a versatile and skin-loving foundation that not only provides beautiful coverage but also offers skincare benefits and sun protection, making it a must-have for any makeup enthusiast looking for a natural, radiant complexion.