I am new just my photo on back ground

[Holographic Breathing]

Hi I am new to this.

I have a nice photo of myself and with gimp I have cut out the backgrounds and I think the background is now transparent.
The photo is w1008 x h961

I want to add the photo with the transparent background to a larger background -  w18 66 x h9 61

I have saved a background of this size in white and would like to change it to colour that I would like and then put my picture with the transparent background on the top.

I would really like some help to achieving this because I'm getting nowhere.

Many thanks in advance to anyone who helps.

[rich2005]

Several ways to do what you require. One way

Use Image -> Canvas Size to increase the width to 1866  Other settings in there: Center / All layers / Transparency

Add a new layer: Layer -> New Layer. Bucket Fill that layer with color.

Move that new layer under the first layer. 

If complete, you can merge down. That is done automatically when you export as a jpeg or a png.

A quick animation of that: https://i.imgur.com/ZieqrHt.mp4

[sallyanne]

You can be sure it is a transparent background if, in Gimp it shows a checkered pattern in the empty area/background now; and you have the alpha channel selected, save as a png.
Another way would be to put your new background down and make it the colour you prefer then put your saved imaged on top a using the move tool place where you want - It will automatically go to the centre.

[sallyanne]

I meant to say put your saved image on top as a layer, then making sure that is selected in the layers dialog move it to the desired position