I would like to create a 20" x 30" collage

Thanks for the suggestions.  I remembered that my cousin is a graphic designer (it's amazing what one forgets when preparing for one's mum's funeral .......) so after creating a series of collages myself, he will design them, plus individual photos, into the 20x30 layout.

at least this got me started on the edges of photoshop .......  I took a quick look at Mix too - looks interesting!

Given your equipment, timing and skills, it might be better to roughly size the photos and have them printed out as individual pictures then trim to size and paste them on to a 20" x 30" board.

Depending on the number of pictures, for example you might use 24, 5" x 5" photos (or a mixture of sizes) .

OK ...... so I have actually figured a bit more out.  I see that I can only select up to 9 photos, and the max size seems to be 16x9.  So I am considering creating several smaller sheets and then I guess manually arranging them within the appropriate 20x30.

However if there are any other ideas, other more robust apps for the iPad, then I am happy to hear about them

Thx

You can try the Photoshop Mix app - they say you can combine pictures with it. If it runs on your iPad.

I cannot help with informations about ...

... how to set up size, how to create an actual collage to save, create a jpg/pdf to give to a printer

Certainly not PDF, but psd is possible and jpg.

For printing a 20" x 30" collage , the image dimensions should be 6000 x 9000 pixels. I don't know if Photoshop Mix can handle this size.

Fenja