How to create a high res collage of 60+ pictures

Also, you can’t created resolution. Are all of your images high resolution?

I mean, if it took you 1 minute (and that's being liberal) to place the image x 60 that's 1 hour of your time which isn't long at all.

If it's for a publication, I would suggest InDesign and using data merge to place the images for you but again, you're looking at 45-60 mins of pre-work + however long it takes you to learn InDesign / data merging...

The benefit to InDesign is that it's created specifically for magazines, books, newspapers etc so you'll be able to define the exact measurements for the magazine and include your bleed, margins etc, it'll also export it to PDF and even convert your images from RGB to CMYK if you specify the colour profile.

In short, there isn't a magic button that will create a beautiful collage for you - You could maybe download a template but you'll still need to place the images and you'd be restricted (Unless you put more work into it) to however many pictures that template has.