What's new

Editing/Extending/Triming Lines


New Member
Hello all,

My first post here....I'm hoping to get some advice on a basic PS query.

I'm self taught on PS (just basic stuff really) but I manage to do everything I need to for most of the time. I've previously had PS work carried by third parties - who know what they're doing more than I do, but are also quicker than me. However I need to make an adjustment on a file, but I can't work out the best way.

I've attached a JPG of the image and the PSD but with the rugs deleted off it to reduce the file size. You'll see that the image has a white grid separating the 15 boxes. This grid is all 'one-item' and on its own layer. However I need to edit the grid so that the top row also has 4 boxes on it, and thus becomes a 4x4 grid. I know I could just delete the grid and draw a new one, but I'm keen to learn the easy/best way of simply editing it. It's probably a very basic PS thing, but it's something I've never come across before or needed to do. I'm quite experienced in AutoCad, and in that software, we'd 'explode' the grid and trim/extend the individual lines etc and/or draw the new sections on.

Can anyone suggest how I should be doing this, or the correct photoshop terminology ?

Many thanks in advance

Heritage + Regency Collage.jpg



Hi Barnesy
Actually instead of modifying some pixels to line up with the one you have, I think it would be easier to create the 4 x4 grid

1) Turn off you white overlay grid
2) Make Sure under View command that Snap is turned on and also Snap To has guidelines set
3) With the horizontal row selection tool in Add mode, click on the middle 3 horizontal guidelines
4) Switch to vertical column selection tool in Add mode and click on the middle 3 vertical guidelines
5 ) use Select > Modify > Expand with 3 pixels
6) Fill the selection with White

The lines will now look all the same and be crisp and clean
Hope that helps
John Wheeler


New Member
Ah great - many thanks John, I'll give that a go when I get chance tomorrow. Your reply and info is much appreciated : - )


You can save some time measuring and setting up guides by using the Slice tool. Using the tool right click anywhere on the canvas and choose Divide Slice. Set up the vertical and horizontal dividers. Set snap to slices then use the horizontal and vertical marque tools to draw the lines.Annotation 2019-07-06 123941.jpg


Staff member
Just for the benefit of others reading this thread, I have a slightly different approach.

I've made hundreds of these for businesses and I always create them so they are editable. My approach is with using math and the Rectangle Tool. No need for grids or guidelines.

If your document is 1600px x 1600px and you want an 8px white border around all the cells, it's a matter of simple math.

There are 5 borders across and 5 borders down.
8px x 5 = 40
1600 - 40 = 1560
1560 ÷ 4 = 390

Your cells need to be 390px x 390px

Create a Solid Color Fill layer serving as your Background/Border color.
Anywhere on the document use the Rectangle Tool and click
Put in your parameters, 390px x 390px , this creates one cell. (See Note below)
Copy that cell and position with the Move Tool.
Repeat until you have 4 cells. Highlight and group them.
Copy and move the group down. Repeat.
Screen Shot 2019-07-08 at 7.43.33 PM.png

If I want an alternate top row of cells (let's say 3 cells), do the math.

There are 4 (8px) borders across.
8px x 4 = 32
1600 - 32 = 1568
1568 ÷ 3 = 522.5 (approximately)

Your new rectangle must be 522.5px x 390px
Duplicate and position with the Move Tool.
Screen Shot 2019-07-08 at 7.54.30 PM.png

All that's left to do is add in the images by clipping them to any given cell.
Screen Shot 2019-07-08 at 7.55.42 PM.png

You can then add the smaller cells, cell numbers, descriptions, etc.

Note: I intentionally left out that I turn the very first rectangle into a smart object (synced, not linked, smart objects). When this SO is duplicated and used throughout the grid, it's super easy to just double click any of the cells and change it's size which will update all the rest of the cells making it extremely fast and easy to edit! I felt this might be more difficult to understand.

I did not use SO's in my PSD example file.