Determining the proper spacing between bricks, also known as the mortar joint width, depends on several factors including the type of brick, the desired aesthetic, and the structural requirements of the wall. Here are some guidelines to help you determine the appropriate spacing:

1. **Manufacturer recommendations**: Check the manufacturer's guidelines or specifications for the specific type of brick you are using. They may provide recommendations for mortar joint width based on the size and style of the brick.

2. **Aesthetic preferences**: The mortar joint width can significantly impact the appearance of the brickwork. For a traditional look, standard joint widths ranging from 3/8 inch to 1/2 inch are common. For a more contemporary or modern look, thinner joints of around 1/4 inch or less may be preferred.

3. **Structural considerations**: In load-bearing walls or areas with high wind or seismic loads, wider mortar joints may be necessary to provide additional support and stability. Consult local building codes or a structural engineer to determine the appropriate joint width for your specific application.

4. **Consistency**: Whatever joint width you choose, it's important to maintain consistency throughout the wall to achieve a uniform appearance. String lines or spacers can help ensure consistent spacing between bricks as you lay them.

5. **Allowance for expansion and contraction**: Leave space between bricks to accommodate thermal expansion and contraction, typically around 1/4 inch to 3/8 inch. This helps prevent cracking and damage to the brickwork as temperatures fluctuate.

6. **Test layout**: Before laying bricks on a large scale, it's a good idea to do a test layout to determine the optimal spacing and alignment. Lay out a small section of bricks with different joint widths to see which option best suits your project.

By considering these factors and guidelines, you can determine the proper spacing between bricks to achieve both structural integrity and the desired aesthetic for your brickwork.