I love the flex on these nibs, this is my go to nib for great line variation, it makes a fairly narrow line with little pressure but becomes very thick as pressure is added!I highly recommend this nib.

When I write letters now I chose this nib over all others because of this amazing line variation as well as the many color variations I can achieve with this nib from my high shading fountain pen inks

These nibs are very, very flexible, allowing a great variation in line width

This G-Pen is flexible, it has great width variation and seems to be made of durable material

Good line width variation, ink flows smoothly down the nib