DPI Explained in 5 Minutes

[@danieljamesryanphotography]

"Are these 300dpi" Been hearing it for decades from customers who think they know everything. I can't wait to refer them to this video.

[@TechnicallyTrent]

Glad it was useful!

[@susan2445]

This might be a stupid question but here goes anyway. You explained what happens to an image when it's designed too small for it's printed space but what happens when an image is designed, let's say, twice as big for it's intended printing space? Are pixels removed or perhaps two pixels mashed into one pixel? If I missed that explanation in your video, my apologies, just tell me to watch it again.

[@TechnicallyTrent]

Hi Susan, good question! Reducing the size of an image is also called "downsampling". There are many different algorithms to do it that give different results, including the methods you mentioned. If you downsample by 50%, you can just throw out every other pixel. Or the program can intelligently try to take the average of adjacent pixels to create a new pixel. They all have pros and cons. The con of "throw out every other pixel" method is that if you have a 1-pixel-width line, it could totally disappear. The con of the average method is that sharp edges can appear blurred. But the good news is that for most practical applications, downsampling isn't going to result in noticeable quality change. If you have a 4000x4000 image and need to scale it to 2000x2000 to put on a tshirt, it is probably going to look fine. I'd say the problems start to occur when you get into that sub-512 range where things need to be pixel perfect like with video game art of precise logos. Hope this helps!

[@Pablo22578]

Yeah if you have a 4000x4000 300dpi image and make it 2000x2000 in photoshop but resample, the image effectively becomes 600dpi

[@bobobob1230]

​@@TechnicallyTrentvideo game textures is a great example

[@gbxgbxgbx]

@4:35 pretty sure it's not just a calculator - the ppi you give and save there will be stored in the image's meta data, and used whenever you want to print this image alone. It will be applied when printing the image - try it. :) That's why there is a 'default' for this ppi, being 72 or 96ppi so when you right click print the image - you would get 'roughly' the same size image as displayed on the monitor. (very roughly nowadays because the screen size/resolution vary so much - but back in the day it was almost always 72ppi for mac or 96ppi for windows.

[@TechnicallyTrent]

Hi @gbxgbxgbx, good point, the metadata may be used by some programs. But people really need to understand that metadata is just a suggestion and many programs will ignore it. A lot of people use their images for print on demand, and those sites just care about the pixel resolution.

[@gbxgbxgbx]

@@TechnicallyTrent Yes. There still is a lot of confusion reg. the ppi/dpi even in the graphical field.

[@shrimp_boogaloo]

Cheers Trent, super clear and helpful!

[@jamescollins6179]

Thank you for the clearest explanation I have found. Would you help me with another problem? I have tried several AI image generators on the web but none allow me to request a specific image size before creating the image. So, to meet the printable area required for a product I am forced to resize the image, eighter removes part of the image or if I crop/stretch I loose pixels. I understand the only way to solve this is with an API? Thanks

[@TechnicallyTrent]

Hi @jamescollins6179, thanks for watching! It depends on the AI generator you use. Most will not allow you to specify pixels, but you can set the ratio. So for example, if you need a 2400x3600 pixel image, you can't specify that exact size, but you can specify a ratio of 2:3. MidJourney works like that. From there, you can upscale your image. Hope this helps! Trent

[@jamescollins6179]

@@TechnicallyTrent Appreciate quick response and will go through your other videos to learn more. Thanks

[@gga3053]

Very helpful! Thank you.

[@TechnicallyTrent]

Glad it was helpful!

[@bobobob1230]

yards option might be for fabric designers?

[@TechnicallyTrent]

Possibly...I suppose it can't hurt to add it :)

[@Sanchan]

The best video about DPI. You're only one saying this. I did a screenshot comparison on the file preset creation on Affinity Photo, and it doesn't change in the preview. I have a couple questions. This is what I do, I put my 72 dpi into a 300 dpi canvas then export so it has the dpi information for websites the need high dpi designs. I don't know if doing this does anything besides letting the sites know its 300 dpi. Am I destroying my image in any way? I thought about using the resize document or pixel document, but what when I do it makes my file MASSIVE (pixel resize on Photo 2) then when I resize it down to fit the canvas, its DPI is +300. (I dont think i should use this) I don't know if I should be resizing 72 to 300dpi with resample, OR how I do it where I just create a canvas thats 300 dpi (I sometimes use Procreate and export in 300 dpi).

[@Sanchan]

I also have a second question. Doing things correctly how you have said, I have a image that exceed a bit from the canvas. I want to use the image, so I scaled it down by clicking the corner and drag so it fits how I want it. I'm scaling down. Is my image more crisp doing this or am I damaging the end result? Thanks again. Your 2 videos on DPI are incredibly informative.

[@TechnicallyTrent]

Hi @Sanchan, thanks for your comments! Regarding your original comment, I'd encourage you to look at what the pixel resolution is for the files before and after you export it. That is what really matters. I'm not sure if you saw it, but I have another video that talks about DPI in more detail: kzbin.info/www/bejne/e4HCaXlqhs93ppI For your second question, usually downscaling your image by a little bit is pretty safe, especially for things like photography. However, if you have graphical designs with well-defined edges (like vector artwork or text), it is possible that downscaling can ruin some of the edges. If you have some parts of the image with shapes/lines that are 1 or 2 pixels wide, they could possible be lost or blurred. I recommend doing a careful visual inspection after downsizing to see if the quality still meets your needs. Your questions make me realize that resizing images in Affinity Photo is a topic I should make a video for in more detail. I'll add it to my TO DO list, so stay tuned for that :)

[@Sanchan]

@@TechnicallyTrent Yes, I did see it. You didn't really give direct answers, but thats okay. I didn't mention that the size of the image and canvas is the same. So, I guess 72 dpi on 300 dpi with same size dimensions doesn't mean much to alter the image quality. I did size them down a lot to fit how I want to in canvas. I will look into other people downsizing on KZbin to see their results. I will also look into my images from 72 dpi to the downsized versions to compare. I think that would be a great video.

[@TechnicallyTrent]

Hi @@Sanchan , yes, if the pixel resolution is the same, then DPI does not mean anything. What DPI is useful for is when you create your document in inches. Your document is still pixels, but it just says "DPI" and "Inches" to help us calculate. All it is doing is just creating a document in pixels that is DPI * Inches _Height by DPI * Inches_Width. Hope this clarifies a bit!

[@justanoob7030]

very well explained. Thank you for clearing this up for me!

[@TechnicallyTrent]

No problem!

[@Jmarique]

Question: what if you're trying to go the other direction? Can I use an image that is 6,000px X 9,000px( a 20x30 in print) and size it down to 2,400px X 3,000px ( a 8x10 in print)? Or would that not work as far as image quality?

[@TechnicallyTrent]

Hi @Jmarique, thanks for the question! Generally, downscaling (reducing the size of an image) isn't a problem, especially for photographs. However, if you have graphics-based artwork with fine details like 1-pixel width lines or dots, it's possible those little details could be lost when downscaling. If downscaling, I recommend checking your image again to make sure it still meets your quality standards. Hope this helps!

[@andrewphillips342]

Thanks Trent!

[@Adamb20]

What program are you using

[@TechnicallyTrent]

Hi @Adamb20, I am using Affinity Designer in this video. I have many tutorials on that program on my channel, so check them out if you want to learn more about it :) I also have a 2-hour crash course for the program here: kzbin.info/www/bejne/bqqYdHejf7inbsk

[@Adamb20]

Thanks, man. I really appreciate your help, for this is my 1st time trying to start a t-shirt business . Finding the learning material is a job in it's self there's a lot of misinformation, plus overthinking doesn't help 🙃

[@Shizui_Editz]

Very helpful thanks ❤

[@Pablo22578]

Good video, you are slightly wrong about file creation in, say Photoshop. When beginning a new file and the drop down gives dpi settings options (they are basically ppi) but the program most certainly changes the res per inch when doing so.

[@TechnicallyTrent]

Hi @Pablo22578, yes, when creating a document in Inches, the DPI (or PPI) will be used to multiply the inches to get the pixel resolution. However, if you are creating a document in pixels to begin with, the DPI is essentially meaningless. it only seems useful on the creation screen when toggling back and forth between inches and pixels.

[@phaniindra4353]

Is 200 dpi good for pod pls tell me and its in png

[@TechnicallyTrent]

Hi @phaniindra4353, I recommend looking at the POD provider's requirements to see if 200 dpi is sufficient. Some big products (tapestries, blankets, rugs) only require 150 dpi. However, smaller items like tshirts and journals usually need 300 dpi for best results. If your image is too small, you can try using upscaling tools like those on Canva. Hope this helps!

[@user-wh4wm3mw7l]

In Photoshop, does PPI value affects performance?

[@TechnicallyTrent]

If the resolution of your image is very high, that can effect performance, especially if you have lots of live effects.

[@soscott212]

so basically if you’re not planning to print at all, dpi doesn’t matter? can i just set it to the lowest if i’m just planning to keep and post it strictly digital art? (asking so i can have max layers)

[@TechnicallyTrent]

Hi @soscott212, DPI will not matter, but the pixel resolution will. So make sure the pixel resolution is of a quality that is acceptable for your digital work. For many apps, if you create the document with "Inches" and "DPI" specified, it will create the document in a resolution that is Inches X DPI. So in that scenario it is used in the calculation to create the pixel size of your document. But all that really matters is that pixel size.

[@soscott212]

@@TechnicallyTrent okay great! thank you 😁

[@jamescollins6179]

When you can I would like to see a video on AI tools that can increase the resolution of an image. Also, a video on API (Application Programing Interface) which I understand will direct AI image generating site to generate an image to a custom size. Thanks

[@TechnicallyTrent]

Hi James, thanks for the suggestion! I have several AI videos planned, so stay tuned!

[@panoramapalacevirtualtours]

I created in meters so i could get a real size pixel calculated for a gigapixel print :)

[@TechnicallyTrent]

Wow, sounds like a big print :)

[@panoramapalacevirtualtours]

@@TechnicallyTrent maps.app.goo.gl/A1Rb19sbHacY488G9?g_st=ac Replacing that photo with a 200megapixel photo but sending it already in that format to print. So it was fun to measure and make the same shape and send it in the right shape to print 👍👍👍

[@mestayno]

I only work in yards

[@TechnicallyTrent]

I guess you're in luck because Affinity programs support yards ;)

[@mestayno]

@@TechnicallyTrent 😎🤙