Resize Canvas WITHOUT active "Merge all Layers"?

[pstein]

Occasionally when I click on "Resize Canvas" for a PNG file then PSP automatically activates "Resize all Layers" feature.
I have to click on "Merge all layers" toobar icon to get a pure white background "as usual".

Strangely this happens not always but only sometimes.

How can I achieve that PSP always automatically enlarges canvas without creating multiple layers?

[Forriner]

Open the Layers palette in PSP: menu View/Palettes/Layers or F8 to toggle the palette.
If the image you are viewing has a 'Background' layer and you increase the Canvas Size, PSP will fill the extra space with the background colour you specify in the dialogue. Any other type of layer will get transparency.

A PNG file can support layers and transparency just like a PSPIMAGE file. The file you open may not have a Background layer but only a Raster layer. Resizing (enlarging) the canvas then adds transparency. Merge All not only merges layers, but makes the result a Background layer. That's probably why it doesn't always happen: one PNG has a Background-type layer, the other only Raster-type.

Note that when you create a new file through File/New... or Ctrl+N, when you specify the size etc. you can also specify the background colour. If you specify a colour and click OK, you get a Background layer with that colour. If you specify "Transparent" you get a Raster layer with the checkerboard pattern for transparency.

The attachment shows a few of the layer types in PSP. If the layer name has been changed, the icon on the left shows the layer type. I hope this helps a bit.

[hartpaul]

Occasionally when I click on "Resize Canvas" for a PNG file then PSP automatically activates "Resize all Layers" feature.
I have to click on "Merge all layers" toobar icon to get a pure white background "as usual".

Strangely this happens not always but only sometimes.

How can I achieve that PSP always automatically enlarges canvas without creating multiple layers?

When you mention Resize Canvas do you mean:
1. Image > Canvas Size which does not have a Resize all layers feature
OR
2.Image > Resize which does have a checkbox under advanced settings for Resize all Layers

You are not clear on the type of image you are working on except that it is a png file. A png file does not show as a Background layer as a Background layer does not support transparency.
a) Does your png file have transparency?
b) Is it a single layer or many layers, - how many?

We need to know all the information to be able to try and duplicate what you are experiencing.

Are you wanting to keep the transparency when you do a resize or do you want to merge 'all layers' to lose transparency.

Or do you have a number of layers and want to resize one layer only.