When painting Inside walls you must remember to do all the prep work. In this particular case we have to sheet rock some holes in the wall to make it all even. This process Requires to allow the sheet rock to dry before painting. Once it is full dry you must remember to sand the patches till they are smooth. After doing all the prep work You must make sure to cut the wall: this process includes using a brush to paint the top of the room, bottom and the edges around the windows and doors.
As you can see in the picture the cuts have been made around the doors windows and at the top and bottom of the base.The next step once all the cutting has been done is to use your roller and roll all the walls. Once the walls are all rolled,you then start putting the vertical lines with tape making sure they are all equally spread apart. Once you Have finished that color you Repeat the process with the secondary color. Making sure that you let the paint dry completely before removing the tape is extremely important. once it is dry you peel it off slowly and enjoy your wall.