Get Blue Gel Pen Drawing Background. I know i'm not the only one that loves and hates the this set contains 10 colors: For this type of drawing all you need is.

Sakura Gelly Roll Metallic Gel Pen 1 0 Mm Blue Black Jetpens
Sakura Gelly Roll Metallic Gel Pen 1 0 Mm Blue Black Jetpens from static2.jetpens.com
However, black gel could also be used. Stationery gift sets & bundles. Others to get a general idea for the space and may not be to scale really.

The drawing took 1 hr to complete.

Some drawing are to figure out details architecturally. A set of gel pens can round out any collection of craft supplies. This video is a great place to start. A few of new drawings, as usually ink pen at paper.