Query about blurred line graphics on coloured backgrounds

[De09]

I needed to create an image that included blurred lines, and I made this:

Procedure

– I generated the lines, as paths, in InDesign, because that’s the application I know best, then added the blurring in Photoshop
– I saved the resulting image in the following formats: EPS, JPG, PNG, TIFF, hoping that in at least one of these cases the result could be imported back into InDesign and the transparent background would be retained, and I could then place the graphic onto a dark background (I don't know how to do that in Photoshop)
– This doesn’t work. When imported into InDesign the image appears with a solid white background instead of a transparent one. I tried various effects, such as “darken”, “lighten”, “multiply”, and none are right
– I can't use clipping paths around the lines, because the lines are blurred and need to remain so. Lines with sharp edges won't work for what I need here

Questions

– How does one make coloured, blurred lines and place them on a coloured, non-white background?
– What’s the best way to do this? Should the artwork be made in Illustrator instead? Or Photoshop? Or InDesign? Ultimately the image needs to come back into InDesign so that type can be placed on top of it

Any advice on how best to do this would be much appreciated.

I have: InDesign 2025, Illustrator 2025, Photoshop 2024, on Mac OSX Ventura 13.4

[LAMY2017]

@De09, the question immediately springs to mind -- what does the file look like in Ps, i.e., is the background checkered pattern displayed? Can you post a screenshot of Ps, or the PNG?

[De09]

Thanks for your response, Larry. The image above actually is the PNG. When viewing the various versions (EPS, JPG, PNG, TIFF) in Photoshop, the background is white; I don't know how to make it transparent in Photoshop.

[jane-e]

When viewing the various versions (EPS, JPG, PNG, TIFF)

By @De09

• EPS is obsolete. Skip this one
• JPEG does not support layers
• PNG does not support layers
• Use either TIFF or PSD. InDesign supports both of these. Use File > Place.

If there is a Background layer, rename it to make it a pixel layer or just delete it or fill it with the new color. 

Jane

[De09]

Many thanks, Jane. I didn't actually know that Photoshop files could be placed directly into InDesign.

There was no additional background layer. In the end I went back to InDesign, coloured the lines as needed there, exported that as a colourless-background PNG, imported that to Photoshop, created a coloured layer behind the PNG artwork, and then flattened the result. Whether this is any sensible route I don't know, but it seems to have worked for now.

[jane-e · Accepted solution]

@De09 

It occurs to me that you could also do this: in InDesign, fill the Frame with the color, then place the transparent PNG into the frame.

Flattening the image turns it into one Background layer, so be sure to keep a copy of PNG.

Jane

[De09]

Many thanks, Jane.