From my personal point of view :-) When I design a kit, the very last stage is to "optimize" each file... and I always spend time on this task. So mine are altready optimized... so you wouldn't have to reduce their size.
I'm sure that most of the designers in the SBM store optimize them.
If you reduce the size, you lose quality... depending of the size of your pages.
I know some designers (no name :-)) who don't optimize them and the result is that for 100 embies you have about 180 Mb!!! if not more!
What you could do is use an external disk to store your kits...
Also note that if you have to reduce the size of each item of many kits it will be a VERY FASTIDIOUS task! and very long..
Sandrine, What is your interpretation of the word "optimize"?
I always try to flatten my layers on .jpg images and trim excess on .pngs and also reduce size if originally made large to view detail as they are being made. Will group layers or merge visible on .png files before saving too.
Optimize? means optimize. LOL. Seriously. I can't explain this *process* in just a few words. I'm going to give you some tips...
When you design, you should perform different steps... same thing when you develop app.
You should define what you will do and how... ie the theme, the palette, the list of embies and papers... if you need to create new shapes for your embies, new texture styles...
Once done, you start to design.
You have to create new stuff from scratch (shapes, styles...) and to "customize" existing stuff.
Test your styles to have an idea of the final weight of your embies once the style is applied... An embie is a series of layers with styles which determine the final weight, as well as the size of your original document, of course (always work in 300 dpi).
For new stuff you should "test" each new embie... papers... the best way is to create quickly a page in SBM and to export it as .jpeg - 300 dpi - 3600 x 3600.... and then you zoom +, +, +... to check any detail. You can also print.
Once everything is created, you should optimize all your files.
First, remove all the "blank" space around the embies and check your embies aren't cut...
If you use CU, PLEASE apply a COLOR AROUND the object (a different color of the object - 10 px)... Use the zoom... so if there's any LOST PIXEL around the object you will see them immediately.
You should check the size/weight of each of them: pixels - Kb or Mb and reduce it if necessary.
TAKE AN EXAMPLE:
A flower... 1000 x 1000 px is fine... 300 x 300 px is TOO small.
The weight of your file is 2.5 Mb... it's TOO heavy... You should try to reduce the size and you should get a lower weight.
For the papers...
5 Mb is TOO heavy!!! You shouldn't have papers whose weight is higher than 3 Mb... and I would even say 2.5 Mb. Try to reduce the quality option... but don't select a value lower then 7. Check if you have unuseful layers... idf yes, remove them, and save again.
So that's some tips...
To conclude you should review all your files, and zoom at the embies/papers to detect any issue :-)