1. Embossing Quality: Ensure the Braille is well-embossed, with clear and raised dots that are easy to read.

2. Material Durability: Look for Braille printed on durable materials, especially if it's for everyday use.

3. Dot Height and Spacing: Check that the dots are spaced correctly according to standards (typically 0.09 inch apart) and are raised sufficiently (at least 0.025 inch).

4. Contrast with Background: Ensure there's good contrast between the Braille and its background for visibility.

5. Consistency in Style: Look for consistent font and dot styles throughout the material, as inconsistencies can confuse readers.

6. Braille Grade: Be aware of the difference between Grade 1 (uncontracted) and Grade 2 (contracted) Braille, depending on the user's reading level.

7. User Friendly Design: Consider the layout — navigation should be intuitive and easily accessible.

8. Educational Resources: If purchasing educational material, ensure it's aligned with recognized educational standards for teaching Braille.

9. Testing with Users: If possible, let a Braille reader assess the product before purchase to ensure it meets their needs.

10. Accessibility Certifications: Look for products that have been certified for accessibility by reputable organizations.

11. Community Recommendations: Seek recommendations from local blindness organizations or communities for trustworthy sources.

12. Return Policy: Check if there’s a return policy in case the Braille does not meet expectations.

By keeping these tips in mind, you can ensure that you find quality Braille materials that meet necessary standards and user needs.