When using less than 100% infill it is too thin and misses bits

So in the past I've usually printed at 100% infill because what I was printing needed to be strong. But what i am tryign to print now is a prototype and needs to print in less time than 6 hours like it would with 100% infill.

So I've choosen 30% infill.

Printing 0.4 width, 0.25 height, 0.35 nozzle.

The infill strands are approximately 0.25mm wide, sometimes missing bits and with blobs at the ends against the perimeters.

With 100% infill I don't get any issue like this and it looks good...?

I'm using Gen7, Marlin, J-head mkv

Any insight?

Sorry about the picture quality, my phone doesn't do the best job.

That is because you are using straight infill. With straight infill it is not being stacked on top of the layer below. Instead the layer that it is being stacked on top of is actually 2 layers below. If you use hex infill instead you will not have the issue. You could also increase the extrusion width for the infill to try and extrude enough that it sticks to the layer 2 layers below. But then you will most likely need to slow it down for the infill because of the greater volume being extruded.

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