How to make chalk texture with pencil

first, we have these pencil hand letters on sketch book. we need scan it in to computer with at least 400 dpi.

then, adjust the level of the image to lost all the highlight detail( i mean the white background) . then select the image from channel. then, lock the empty space and color it with brush. 

i have this blackboard image, directly pull from google.

dada~ put the blackboard layer under the letters~