nothings wrong with the png file, it's me who misunderstood your question.
I assumed you were doing a view in an idw and while it's been yrs since I had to detail something where I used a perforated sheet metal image, I recall back then there were some things that didn't work right or something or another.
Time for me to sit back and take it all in since I'm 2 versions behind.
Sorry for the confusion!
I can use the image file as an image but I can't use it as a cutout image.
And I need the holes to be transparant so this isn't a solution for me.
I have found a solution. Instead of using the png-file to cut out the black circles, I made those circles transparant and used the image as image. Inventor makes transparant what is transparant in the image
This is actually a very important point that appears to be undocumented.
Reading through the wiki help, it will say that shaded modes will not make use of the custom "cutout" image. If you strictly use realistic visual style you will be OK in creating your custom image file and its corresponding cutouts image in photoshop.
The problem comes when you would like to create a custom material (with some transparency) that you need to be displayed correctly in the shaded views on a drawing or in your assembly environment. You will then need to create a png file with transparency in photoshop and use that as Nick has stated.
To summarize, if you use all the visual styles and you create any custom materials/appearances (like expanded metal), you must create a png file with transparency as well as a cutout image and place both into the appearance editor.
thanks Rob & Nick you have found the missing piece of the puzzle!
i was just working on one of my own appearances tonight and it was behaving a bit randomly until i used your concept.
i have attached a snapshot of my appearance which works fine in shaded mode & in realistic mode. as you say there is no mention of this in the documentation. i just read through the help and it would appear to be lacking in a few areas.
ps- the only thing i have not figured out is why my old mesh bitmap file still is able to display transparent sections when i use it for the image. it is still able to show up in inventors shaded visualisation just like it always has in pre 2013 versions.
i recall maybe that in earlier versions, inventor used a method that was based upon whatever the pixel colour in the lower right corner of the image was. if it sees that same colour pixel elsewhere it makes every occurence of it transparent when is maps it into inventor.
for testing, even when i copy my old mesh image it to make a new pattern, i cannot get the copied file to work at all.
thankfully my cheap little snagit software is able to give me transparent backgrounds where i need it to.
re following on from my ps above, for getting the the old pre 2013 transparent image sections to work, i remember that if you want the transparent pixel method to work then the file needs to have a symbol as part of the file name, namely the & symbol as the very last character berore the .png or .bmp