Needles vary in three specific ways-- Eyes, Points, and Size (or "Weight"). Each of these factor into what the needle is best used for. In regard to threading, we'll be talking about Eyes.
The Eye of a needle is the hole where the thread goes through. On machine sewing needles, the Eye is located at the point, while hand sewing needles have it at the opposite end (this is one of the numerous reasons why NOT to interchange the two).
The smaller the Eye, the harder to thread. Makes sense, right?
So why all the different options?
Singer needles come in various sizes ranging from the 8 (small) to the 18 (large). As the needle gets bigger, so does the Eye. As you can see from the picture, the Size 18 needle's Eye is wider than the Size 8's shaft.
Small needles are for delicate projects where you don't want to leave holes in the fabric.
What if the Size 18 Eye is still too small?
Here are two options:
1. Top Stitch Needles. Top Stitch Eyes are long and wide and can be purchased in Size 14 (which is the Standard needle size)
For more information on needles, check out our YouTube tutorial: