Advice for painting a bedroom?

Specifically, I am planning a twelve inch stripe horizontally across a bedroom wall. I'm having trouble making the lines perfectly straight, and if I goof it, it'll look terrible! Any suggestions?Advice for painting a bedroom?
Yes i have been painting over 30 years painting lines is an illusion i will explain, when people glace as they walk by all they do is glace. Painting is a gift i have trained many painters iam going to give the tip on painting straight lines. First of all you our only as good as the tools you have so having a good nylon brush is very inportant. No home has perfect walls corners or always off so this is what you do wall to ceiling ride off wall onto ceiling 1/8 of an inch this is how we straighting crooked framing. Like i said its just an illusion same why on painting you base because of the framing where you may have 1/4 inch and a stud 2x4 is not lined up. You also ride 1/8 of an inch capping the base onto the wall and perfect ever time very easy you will look like a pro. Next is the back band this is the edge of you caseing paint it first than let your brush fall ( slide ) down the wall let it do the work do not force it with the paint in the brush it will do the work. To get you paint to hold in your brush better dip in work pot and slap side ways do not wipe your brush off on the can. After you do this like i said take your brush and go up and down in the work pot you will see it stays in the brush. You do this and you will love you paint job. The more paint in the 2 inch of the tip of you brush is easyer to paint with.





NOTE : If you use tape the paint can go behind it 85% of the time waste of money and time.Advice for painting a bedroom?
try looking around for a paint edger, i dont know for sure if it comes in a 12'; length or not, but i do know they have a 9'; edger, if not then use painters tape and as suggested before with a laser level and role out only 6'; at a time for the tape will sag at any longer length


happy painting
Try some painter's tape. It's with the painting supplies. Use the tape to make a line where you want it on the wall, use a level to make sure the tape is not sloping upward or downward, then just keep it between the (tape) lines! Good luck!
get masking tape or painters tape to mask your lines then paint and pull off the tape your lines will be crisp and straight, also get a laser level to level your tape
Measure down to where you want the lines at intervals so the line is straight then mark the entire length that you have marked with 2 lines of tape. Then paint between the tape.
I agree with Nickwb1 only use painters tape (sometimes masking will not stick) and you can put a thin line of glaze over the tape this will keep paint from getting under the tape if your wall isn't smooth.
measure the height of the line off floor or ceiling along the wall


connect the dots


tape it off
use one of those laser tape measures to mark the end points then use a good orange or blue painters masking tape to connect the ends points.as for the scorpions in your house i wouldnt be much help because im a pisces but id suggest you lay some sand in your living room and maybe a few cactus plants and siders to make the scorpions feel at home.