Exporting Slides to PDF creates huge files

Hi ​@Heather_Tompkins ! 

My name is Ben - I build export plugins so I’ve done a lot of file size testing :)
 

Images & Dimensions

I find often what hurts file size the most is either designing at dimensions that are too large, or using images that are too large. 

PDF exporting is very different from image exporting. Let’s say you import an image into Figma that is 1000x1000 pixels. If you scale that image down and put it inside a frame that is only 200x200 pixels, and then export the frame as a PDF - all 1000x1000 pixels are actually still “inside” the 200x200 PDF. 

This is different if you exported that same frame as an image. With image export the output file is actually only 200x200 pixels, unlike the image in our PDF.  

So now, let’s imagine you have a slide deck, where each slide is 1920x1080 pixels. And now you import multiple high-res images (e.g. 10 images at 2560x1440 pixels each) and put them on your slides.

Well, now you are essentially packing 10 * 2560 * 1440 = 36 million pixels into one PDF file. That might make it clearer why the files can get so large when images are being used. It can take roughly 5-10 MB to store those images alone, apart from the other PDF file data. 

Also keep in mind that certain artwork can end up as an image in the PDF, even if it was vector in Figma. For example, certain effects like shadows or gradients may be rasterized. 

This is not really made clear, and Figma’s vague “quality” options don’t help much either. But it’s actually a “feature” more than a bug - we want the ability to control the resolution (DPI / PPI) of images in our PDF, because sometimes we only want them to be 72 dpi for digital, or 300dpi for print. The problem is that Figma doesn’t give us control over image downsampling with native PDF exporting. 

So how do you solve this?

1. Only import images at the resolution you need, rather than the highest res version.

2. Downsample images on export - you can do this with many export plugins.

What else?

If you check and make sure you’re not packing too much into the PDF, but you still have a large file size, let me know and we can try and troubleshoot more. 

P.S - my plugin Print for Figma has tools to help you check image resolution as well as downsample images on export. You can get unlimited exports for a month for $12 USD. BUT there are also other export plugins out there that may be better suited for your needs!