To custom order a square umbrella, you will need to follow these steps:

1. Define Your Requirements: Determine the specifications for your custom square umbrella, including size, color, materials, handle type, canopy design, and any additional features like UV protection or wind resistance.

2. Find a Manufacturer or Supplier: Look for a reputable manufacturer or supplier that specializes in custom umbrella production. You can search online, ask for recommendations from colleagues or industry contacts, or attend trade shows to find potential suppliers.

3. Contact the Manufacturer: Reach out to the manufacturer or supplier and discuss your customization needs. Provide detailed specifications for the square umbrella you want to create, including any branding or logo requirements.

4. Request Design Mockups or Samples: Ask the manufacturer to provide design mockups or samples based on your specifications. This will allow you to visualize how the custom square umbrella will look and make any necessary adjustments before production begins.

5. Confirm Pricing and Terms: Once you are satisfied with the design and samples, confirm pricing, payment terms, and production lead times with the manufacturer. Make sure to clarify any additional costs for customizations or artwork setup fees.

6. Provide Artwork or Logo Files: If you are including branding or logos on the square umbrella, provide the manufacturer with high-resolution artwork or logo files in the required format (e.g., vector files) for printing or embroidery.

7. Place Your Order: Once all details are finalized, place your order with the manufacturer. Make sure to review and sign any contracts or agreements outlining the terms of the custom order, including specifications, pricing, and delivery details.

8. Review Production Proofs: Before mass production begins, the manufacturer will provide you with production proofs or samples for approval. Review these carefully to ensure they meet your expectations in terms of design, color, and quality.

9. Production and Quality Control: Upon approval of the production proofs, the manufacturer will proceed with mass production of your custom square umbrellas. During production, they should conduct quality control checks to ensure consistency and adherence to specifications.

10. Shipping and Delivery: Once production is complete, the manufacturer will arrange for shipping and delivery of your custom square umbrellas to your desired location. Make sure to coordinate delivery logistics and provide any necessary shipping information.

11. Inspect and Accept Delivery: Upon receiving your custom square umbrellas, inspect them thoroughly to ensure they meet your specifications and quality standards. If there are any issues or discrepancies, communicate them to the manufacturer promptly.

12. Provide Feedback: After receiving your custom square umbrellas and assessing their quality, provide feedback to the manufacturer. This can help them improve their products and services for future orders.

By following these steps, you can successfully custom order square umbrellas tailored to your specific requirements and preferences. Effective communication with the manufacturer is essential throughout the process to ensure a smooth and satisfactory outcome.