Frame properties that affect the transparency or background colour of tifs.

[Sarah25609949hyau]

I've inherited an InDesign document which has someting going on that I've never seen before, which I'd like to understand!

It contains a number of line drawings on a grey background (ie it looks as if the drawings have a grey background). All the images are TIFFs and if you open those files in Photoshop they all have a white background and contain no layers, no paths etc.

This is the weird part: If I create a new frame in the document and place a new TIFF line drawing in it, the drawing has a white background, and the grey doesn't show through. But if I copy one of the existing frames, which shows the  grey background through the drawing, and link to the new file - voila, the grey background shows through the lines of the new drawing as if it had a transparent background. 

In fact, I've just dragged one of these over to a different part of the document with a green background, and the green shows through too. Basically, there is some property in the frame that is giving the TIFF some transparency. 

I'd really love to know what is going on - just in case I'm ever called on to recreate it!!

[Robert at ID-Tasker]

Is it a Black&White bitmap? 

With Black&White bitmaps you can set "black" to whatever color you want - and "white" will be transparent.

[Sarah25609949hyau]

I'm not sure - I'll have to investigate that. I thought that bitmap was a different file format to TIFF. 

Would that black/white/transparent setting be an option in the frame? The same files behave differently depending on the frame they are placed in. 

[Robert at ID-Tasker]

TIFF is a file format - bitmap is a different thing - it defines how much info is stored per pixel. 

Bitmap - 1bit - 1 or 0 - black or nothing. 

RGB - 3x xbits. 

Grayscale - 1x xbits. 

CMYK - 4x xbits. 

Etc. 

Xbits - most of the time 8 bits / 1 byte. 

You can save each of those as TIFF. 

[Peter Spier · Accepted solution]

A grayscale .tif with the frame set to a multiply blending mose would also show the background...

[Sarah25609949hyau]

Thank you - I can now replicate the effect! 

[Willi Adelberger]

When you save drawings as 1-bit files you will get that beahviour, foreground color in InDesign if you select the drawing in the frame colors the black parts, frame golors colors the background, transparent frames make it transparent.

In Photoshop change mode to bitmap. Often the steps from rgb or cmyk to greyscale ot bitmap.

[rob day]

Hi @Sarah25609949hyau , A Grayscale image with no transparency can be assigned any color, and its container frame can be assigned a different color.

Here I’ve placed a Grayscale and by default its color is [Black]

If I select the Grayscale’s container frame I can give it any fill color and get a faux duotone effect:

The color assigned to the image doesn’t have to be the default [Black], here I’ve selected the image and set its color to red: