Use Multiple Versions of Same Linked Smart Object Without Increase in File Size?

Question

If I create an empty .psd and save it, it is 461 KB.

Let's say I have a jpeg that is 20.2 MB. If I add it as a linked smart object, the .psd filesize jumps to 124MB. I don't really understand why the filesize has jumped so much given that the file is only linked, but I assume it has something to with generating a preview etc.

What I really don't understand is why, if I now duplicate the linked smart object, the file size increases greatly each time I do so.

• 2 instances of same linked smart object 225 MB
• 3 instances of same linked smart object 320 MB
• 4 instances of same linked smart object 416 MB

This carries on, with each new instance adding around 95 MB to the .psd. In this case with a relatively small file this increase isn't so important, but with much larger files this really bloats the file-size of the .psd.

Given that they are 1. all linked smart objects and 2. all the same linked smart objects, this doesn't make sense to me.

Is there any way to have multiple versions of the same smart object or linked smart object in a psd without ballooning the file-size of the .psd?

Answer 1

I believe that, as I was told when I asked a similar question, that 'Photoshop doesn't store the contents of each smart object instance but it does store a full pixel preview of each', meaning that your use of instances to apply memory retaining benefits does not work in Photoshop the same way you may be familiar with in other programs.

I'd suggest reading the linked question and responses for some other information on the matter, but to summarise it: No matter what way a layer in Photoshop is created and whether it came from a linked or lossy-compressed source, Photoshop is creating a 1:1 lossless preview of each layer for speed and preview's sake that will increase the file size. This is not to be confused with the thumbnail preview that Photoshop can create for the file preview.

Answer 2

A 20MB JPEG may actually have a much bigger footprint. To get the actual memory size, go to the lower left corner of the PS display and click on the arrow to choose Document Sizes. You will see the document size at that point. Each additional layer will increase the file size accordingly.

Even if you open a JPEG file and duplicate that layer, you do not expect the file size to remain the same. I don't believe you can add a layer, any layer, even a blank layer without increasing the file size.