How to add a Halftone effect to an image on No Weed using Adobe Photoshop

Step 1 - Open Photoshop and then open the image (File > Open)

Step 2 - Duplicate the artwork and (if you wish) rename it (Image > Duplicate)  

Step 3 - Convert the image to Grayscale (Image > Mode > Grayscale) 

Step 4 - Now add a half tone effect (Image > Mode > Bitmap) then select Halftone Screen as the method and then ok.
Tip: Ensure the frequency figure of the output is equal to that of the input

Step 5 - The Halftone screen options will now appear: Set the angle to 45° and the shape to round. 

Step 6 - Staying in the Halftone screen options: In the frequency box, set the number of lines per inch. This will affect the size of “dots” the image appears printed as the more lines the smaller the dots. Then select ok. 

N.B. The size of the “dots” is up to you, anything between 6 and 25 Lines/Inch provide good results depending on the image; we suggest this as a starting point, should another combination provide better results, undo the effect and go back to Step 4. 

Step 7 - Convert the image back to RGB colours (Image > Mode > Grayscale) then (Image > Mode > RGB)

Step 8 -  Open the layers window (Window > Layers) and convert the image to a layer by double clicking on the image in the layers window. 

Step 9 - Now save the Halftone effected image in a location of your choice (File > Save as)

Step 10 - Open the Colour Range Selector (Select > Colour Range) 

Step 11 - In this window click on the area of the photo which contains the colour you wish to delete and then click ok. This will most likely be black but may be white if the image is on a white background.

Step 12 - Now this colour range has been selected, delete these areas of the image (Edit > Clear)

Step 13 - Now use this new Halftone effected image to create a clipping mask: - Go to your original image and copy this (Edit > Copy) - Come back into your duplicate image and paste in your original image. - The original image will be on a new layer, ensure that this layer is above your Halftone effected image - if not, simply drag the layer to the top of the layers window. - Right click on the original image layer and select create clipping mask. 

N.B. At this point you may find that you deleted an area of the image which you did not wish to delete. If this is the case, close the working space and open the file you saved at Step 9 and go back to Step 10 and delete white if you originally deleted black and black if you originally deleted white.

Step 14 - Save the image as a PNG and import/place this into Corel Draw or Illustrator to print.