With Adobe photoshop, how do I make lines of a scanned pencil drawing more solid?

I've scanned penciled drawings into my computer. But when I go to paint them in Adobe photoshop, a lot of the lines come out incomplete. Is there a way I can fix this without having to ink my drawings first before scanning them?

With Adobe photoshop, how do I make lines of a scanned pencil drawing more solid?virus

Dimitris' suggestion about using Curves is good but maybe somewhat difficult. Using a Levels adjustment layer is a little easier.

Layer/New Adjustment Layer/Levels. Then move the center gray pointer to the right. as necessary to darken your pencil lines.

With Adobe photoshop, how do I make lines of a scanned pencil drawing more solid?anti virus

you could out line it by hand in photo shop, if you zoom in its easyer, but i think its easyer to ink it i think.
start with scanning at higher resolution ~300+ , then while in scanner settings, adjust contrast , theres also bitmap option, but may be too much pixelation, then in photoshop save as psd photoshop file, then edit, adjust contrast/brightness for your purposes, so don't ink original yet, if needed scan copy and ink it instead,

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You can use the Photocopy or Stamp filter in the filter gallery, adjusting the Light/Dark Contrast and Smoothness to your desired settings. You may also consider converting the drawing to Grayscale (even though it is probably already) and then applying filters. Also, adjusting the setting on your scanner to scan a bit darker than normal could help too.
want a super slick clean line?