yes you can use rulers if you want straight lines, but i wouldnt recommend it when youre first starting out. when i first started i thought it was almost illegal in a sense to use rulers or other mediums to put in my pieces..i was definitley wrong. the only reson i say to chill on the ruler thing for now is because u wanna be able to build yourself up until your able to draw a perfectly straight line freehand..just keep practicing and soon youll be able to draw str8 lines freehand...i mean you u can the ruler if u want say a perfect square box or something with correct measurements, etc...just keep practicing
