Main purpose of making a poster is to make the given topic attractive and colourfull ur not only  required to use a pencil or a pen or a blue or black pen u could also use glitters colorpapers colur pencils crayons and etc . u can also make drawing stick wonderful pics and etc ..
but if ur teacher asked u to use only the pencil or something u supposed  to do it .

  • Brainly User
we ca use pencil as well as black pen and any pen is allowed but most preferable is sketch so that the poster would be realistic and give a clear picture to the reader.
 we can make drawings but the drawings should be informative and creative. We can write slogans and facts to make the poster attractive so that the public will be attracted by the cool information and creative picture....^_^ !!!