Setting transparent colour and file size

[Chrisw5]

Hi,

I have a large number of JPEGs, typically text on a white background, which I need to place on a number of yellow coloured pages in Publisher. I then need to remove the white background of the JPEGs so that the yellow page shows through – which replicates how they print.

 

I have previously used MS Publisher and used a command ‘Set Transparent Colour’ which does exactly what I want and, importantly, makes no difference to the size of the file.

 

There is a similar command in Photo under the Filters menu ‘Colours->Erase White Paper’ which achieves what I want but because it rasterises each JPEG first the file size grows by a factor of around 3-4x. I have tried removing the white background of the JPEGs with a selection tool and saving them as PNGs but the file size when placing the PNGs in Publisher is still significantly greater than using MS Publisher. Is there a way of achieving what I want without significantly increasing the file size compared to simply placing the original JPEGs on the page?

All suggestions gratefully received.

Regards,

Chris.

[R C-R]

1 hour ago, Chrisw5 said:

There is a similar command in Photo under the Filters menu ‘Colours->Erase White Paper’ which achieves what I want but because it rasterises each JPEG first the file size grows by a factor of around 3-4x.

I'm not sure what you mean about rasterizing the JPEGs. JPEGs will always be rendered to pixel (raster) objects in Affinity & saved as such, so it won't matter if you use the erase or any other function on them as far as file size is concerned.

[Alfred]

Select the JPEG layer and set its blend mode to ‘Multiply’. This will make the white parts behave as if they’re transparent, allowing the yellow background to show through.

[thomaso]

1 hour ago, Chrisw5 said:

JPEGs, typically text on a white background (…)

There is a similar command in Photo under the Filters menu ‘Colours->Erase White Paper’ which achieves what I want

Instead of editing each JPG and saving as PNG to preserve its transparent background you could alternatively place in APub the JPG files as they are and set their Blend Mode to Darken or Multiply which lets the white background of the JPGs disappear and the yellow background of the page get visible.

[Chrisw5]

Many thanks to all for the prompt responses. Apologies for the delay, I've been out all day.

Problem solved, so many thanks again, for sharing your knowledge.

Regards,

Chris.