🃏 CardFoldr
CardFoldr is a tool to help you convert a PDF of card grids (say, 3x3 cards per page, several pages of fronts and one page of backs) into a gutterfold PDF: card fronts and backs on the same page, with a foldline down the middle for easy double sided alignment.
The tool is designed to work with cards that are 9 to a page, but can be adjusted to work with other configurations.
CardFoldr runs completely in your browser, nothing is uploaded to a server. You can also download and host it yourself if you prefer. The source code is available on GitHub.
Step 1: Select source PDF(s)
Select a PDF file with the cards you want to convert. The cards should be in the correct order and orientation. If you have a separate file with the card backs, you can select it as the background file.
Step 2: Create Grid
Define the grid for the cards. The grid will be drawn on the cards in red to help you move it to the correct point. You can also define a cut margin which will be shown in blue.
Once you've loaded a PDF file, it will be shown here
Step 3: Extract Cards
You can toggle whether to include cards in the final PDF by clicking on them.
Once you've extraced the cards, they will be shown here, front marked blue, backs marked red