How can I extend the pattern in a group layer mask?

Question

I'm fairly new to photoshop (currently using CC 2015) so I apologise for any incorrect use of terminology and if I'm asking a stupid question.

I created an A6 document and followed instructions to create a watercolour texture background (via fill->pattern of a masked layer group) to paint on, but then it turned out I actually need the document to be A5; I've extended the canvas but the texture now doesn't cover the whole document. I found a make-do solution by duplicating the whole group and free transforming it to the new area on the canvas but I then can't blend the harsh line between the two (original and duplicated) watercolour painted layers - I'm happy with the A6 watercolour I had and don't want to paint anymore so am just copy-pasting to make the A5 I need. I tried starting again on A5 but the watercolour looks different so I obviously did something else with the pattern settings that I don't remember and can't replicate from scratch.

So essentially it boils down to: is there a way to simply just extend the existing pattern? Any help would be much appreciated and thank you in advance (:

Answer 1

Have you considered creating a new pattern from the exisiting one, that you can use all the time? I create patterns from textures by doing the following. it creates a seamless pattern from a texture, without any ends that create seams, that way you can use it on any sized file you want without losing the actual flow of the texture.

1. Create a new square file, 5000x5000.

2. Drag your watercolour texture onto the 5000x5000 and transform it to sit in the top left hand corner, filling only 1 quarter of the page. A ruler line in the middle will help you do this accurately.

3. Duplicate (ctrl J ) the texture layer and transform (ctrl T ) it. Right click the transformed texture layer and select FLIP HORIZONTAL. Drag that layer to the right so its left side matches up perfectly to the right side of the original texture layer. press ok. Hold down the shift key when you drag it across, it keeps the texture level with the original.

4. Select both the Original and the duplicated layer and (ctrl j ) duplicate them. ( You now have 4 copied layers of the original texture. ) With the 3rd and 4th copies selected transform again ( ctrl T ) and right click and select FLIP VERTICAL.

5. Drag these two layers DOWN to fit the bottom selection of the 5000 x 5000 square background.

6. This is assuming the texture is square. if it isn't, adjust the background to fit all 4 copies without any overlapping or edges showing. ( or adjust the 4 layers to fit the square and crop.

7. create a new pattern with the textures. EDIT; DEFINE PATTERN You now have a new pattern, without a seam, and you can add it to anything you want. save the pattern for next time you need it.