Wicked_pdf: PDF sizing different on production & development

[jeremylynch]

PDF very small when created locally, and normal when created in heroku.
I have wkhtmltopdf installed locally (version 0.12.4) and wkhtmltopdf-heroku installed (version 0.12.3)

gem 'wicked_pdf', :git => "https://github.com/mileszs/wicked_pdf"
gem 'wkhtmltopdf-heroku', group: [:production, :staging]

The resolution of both PDF's is the same: 595 × 842
I can't work out why this is happening?

[jeremylynch]

I set the DPI to 300 and PDF sizing was again consistent between production and development