If you want an even spacing between images, you will need to use both gutter and marginbottom, setting to equal heights. Note that gutter expects a number, while marginbottom expects a CSS value. That means, for equal spacing, you would need to enter values like this: If you’re looking for more vertical space, simply add
gutter determines the space between columns. If the border setting is used, it must be less than or equal to the gutter. gutter is an integer value and defaults to 5 You can also go for a tight look by setting both gutter and margin to 0.