Q. Is it true that larger needles, like the #100/16, will leave big holes in my quilt?
A. The diameter of the thread is the most important factor in choosing a needle size. It is always safer to choose too large rather than too small. Using a too small needle is like trying to push a shoelace through a too small eyelet and will result in the thread shredding at the needle. If you see a lot of lint buildup at the needle, either the thread is low quality or the needle is too small. If you choose a too large needle, you might see some needle holes not completely filled by the thread. If that is the case, give the quilt top a good shake and the fabric fibers should close up around the thread and close the holes.
If you are using stabilizer or interfacing on the back of your fabrics, this may affect the ability of the fabric to close back up, due to the stiffness of the stabilizer/interfacing.
Most of the time, we're using cotton fabric in our quilts. Cotton fibers will naturally come back together after a good shake, thus making the 'holes' shrink and fit the thread occupying the hole.