New to 3D Printing - Need help diagnosing print problems

[jurban]

Hi there, I recently started 3D printing and my first project is a series of tiles to use as decor on a blank wall. The print is a very simple rectangle with some flanges to connect to the housing. What I am running into is the print will seem to not be as dense, almost as if it is skipping paths. I have printed multiple colors and some colors print perfectly, others have this issue of missing filament. I have attached a picture of what I keep running into. I really appreciate any and all feedback to help diagnose the issue, thanks!

[Bikeracer2020]

Have you leveled the bed and printed one of the many bed leveling files from such as Prusa printables?

Looks to me as if the nozzle is slightly too close to the bed, you could try altering the 'Z' offse in the slicer by perhaps 0.02mm to see if there is any improvement. This will help to highlight any low or high spots on the bed.

[jurban]

The bed has been leveled, I switched filament colors and it printed perfectly fine, switched back, double checked the bed level and it continued to print like what was shown above.

[Bikeracer2020]

Perhaps the problem is with the filament that is giving you the problems.

Can you try a different filament, some suppliers will sell sample filament rather than buy a full reel?

[airscapes]

use a digital caliper to measure the diameter of the filament in several placed around it's circumference every couple of feet. Take the average diameter, I will take a wild guess that it is about 1.68 not 1.75 .. and put that number in the slicer where it says filament diameter and see how it prints. You are under extruded.. there are many reasons why this can happen, but if you have the issue with one roll and not the other and can switch back and forth with the issue following the filament.. than the filament is the issue.
Good luck