If you need a professional poster, it's easy to do it with Word. You can make better posters than you would hand if you create a box and format it to your needs. Once you're happy with your poster, print it out and make some copies!
Steps
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Step 1. First of all, go to the options on the top left and find "Format"
From there, go to the edge and shadow and click on it. Select the page border and then the settings. Now, choose what style, what color and what thickness you want the border.
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Step 2. After doing this and pressing OK, click on the "View" window on the top left
Click on "Insert Toolbar and Drawings". A section will appear at the bottom of the screen.
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Step 3. If you want a title in your poster, use word art
To do this, click on "Insert" and then select word art or simply click the large letter in the toolbar below.
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Step 4. Then, click on the small "newspaper" in the toolbar (a big A with lines around it)
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Step 5. Drag the box and click on the brush (bottom), then select the same color as the border
It also increases the thickness of the line.
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Step 6. Now, insert your image
You can copy and paste it, or insert it from a file.