To upscale Midjourney images for print, work out the pixels the print needs (inches times 300), divide by your image’s width, and pick the nearest of 2x, 3x or 4x. Smol does that on your Mac for a single render or a folder of them, with nothing uploaded. The table below maps the usual jobs to a setting.
| What you are making | The limit you hit | The Smol setting |
|---|---|---|
| A poster or wall print | Print shops want 300 DPI at full size; a 1024 pixel render prints about 3.4 inches wide at that density | Upscale 4x, output PNG |
| A t-shirt or merch design | Printify builds a 15 × 18 inch area at 4500 × 5400 pixels; Printful asks 150 DPI for non-paper products | Upscale the factor that reaches 4500 × 5400, output PNG |
| A Stable Diffusion or ComfyUI render | Renders often come out smaller than the print needs | Upscale 2x or 4x on the Mac, output PNG |
| A web gallery or portfolio | Large PNGs load slowly | Upscale if needed, then Compress to WebP |
| A folder of 200 renders | Doing them one at a time | Drop the folder, choose the factor once |
How do I upscale Midjourney images on a Mac?
Download the render from Midjourney, drop it into Smol, choose 2x, 3x or 4x and an output format, and run it. The upscaled copy appears next to the original, which by default is left untouched. It works on any PNG or JPG, so it handles images from any generator.
Read the pixel size of your original first (Get Info in Finder shows it). Everything else on this page is arithmetic from that number. Midjourney also has its own upscale options, so check what your account offers before deciding you need a second step.
Smol is a bundled feature of a general Mac app, not a dedicated upscaler. For the honest comparison with a specialist tool, read our Topaz Gigapixel alternatives page, and treat the result as something to inspect at 100% before you print.
What AI image resolution do I need for printing?
AI image resolution for printing is arithmetic: multiply the print size in inches by the DPI your printer asks for. At 300 DPI a 12 inch wide print needs 3,600 pixels across; at 150 DPI it needs 1,800. Printers publish their own floors, and they differ by product.
| Figure | What it says | Source |
|---|---|---|
| 300 and 150 DPI | All files must be at least 300 DPI for paper prints and 150 DPI for everything else; maximum print file 200 MB; PNG and JPG accepted | Printful graphics guide |
| 75 DPI | Minimum accepted DPI for paper products, though Printful strongly recommends 300 | Printful digital print file |
| 38 to 74 DPI | Files in this range are adjusted automatically when Printful generates print files | Printful news |
| 4500 × 5400 px | Printify builds the canvas at 300 DPI, a 15 × 18 inch print area | Printify PNG setup |
A 1024 pixel render at 300 DPI covers 3.4 inches. At 2048 pixels (2x) it covers 6.8 inches, and at 4096 (4x) it covers 13.7 inches. At 150 DPI the 4096 pixel image reaches 27.3 inches. Printify’s own advice is blunt: avoid upscaling low-res web JPEGs, because “you cannot add detail that was never there.” Upscaling gets you the pixel count a print area demands; it does not turn a weak composition into a sharp one.
If you sell on a print-on-demand platform, our print-on-demand upscaling guide goes further on file requirements, and the compress a PDF for print post covers keeping 300 PPI when you send a PDF to print.
Which Smol settings upscale AI art for print?
Pick the smallest factor that reaches the pixels you need, and export PNG for anything headed to a printer. Smol offers 2x, 3x and 4x. Larger files take more disk space and time, so do not go past what the print area asks for.
| Job | Factor | Output format | Note |
|---|---|---|---|
| Starting at 1024 × 1024, target about 4096 | 4x | PNG | Reaches 13.7 inches at 300 DPI |
| Starting at 1125 × 1350, target 4500 × 5400 | 4x | PNG | 1125 × 4 = 4500 and 1350 × 4 = 5400 |
| Starting at 1500 × 1800, target 4500 × 5400 | 3x | PNG | Exact fit |
| Starting at 2250 × 2700, target 4500 × 5400 | 2x | PNG | Exact fit |
| Web gallery copy | 2x | WebP | Then run Compress; quality 75 is a starting point, not a measured threshold |
| Email or proof | 2x | JPG | Use Compress afterward to shrink it |
Can I upscale Stable Diffusion images locally?
Yes. Smol runs on your Mac and sends nothing out, so renders from Stable Diffusion, ComfyUI, Midjourney or any other generator can be upscaled without an upload. Drop the PNG output folder in, choose the factor, and run the batch.
Inside the generator there are other routes. The AUTOMATIC1111 wiki describes Hires. fix as a way to render an image at a lower resolution, then upscale it, and calls SD upscale “not the preferred method of upscaling” except when memory is tight (read 11 October 2026). Those run inside the generation. A separate upscale step on the finished file leaves your prompt and seed out of it.
Keep the raw PNG of each render you care about. If you also want a metadata-free copy for sharing, see our guide to removing EXIF data on a Mac.
What is the workflow for a batch of renders?
The whole job is five moves. You do the sizing once, then every later batch is a drop.
Find the pixels you need
Take the print width in inches, multiply by 300 (or by 150 if the product allows it), and write the number down.
Read your original size
Check one render in Finder. Divide the target by that width to see whether 2x, 3x or 4x gets there.
Drop the folder into Smol
Drag in the whole folder of renders, choose Upscale, then the factor, then PNG.
Inspect at 100%
Open two or three results and zoom in on faces, hands and text. Redo any weak ones from a better source render.
Hand off the master
Send the PNG to the printer. For web, run Compress to WebP on a copy so the master stays intact.
What do AI artists use to upscale today?
Start with what you already have, since it costs nothing. Then decide whether a separate step is worth the money.
| Option | Cost | Where it runs | Good for | Watch for |
|---|---|---|---|---|
| The generator’s own upscale or Hires. fix | Included with the generator | Inside the generation | Adding detail while rendering | It can change the image, and it uses the generator’s memory |
| Printful’s automatic handling | Part of its print file generation | Printful’s servers | Files of 38 to 74 DPI, per its announcement | You do not see the result before it prints |
| A dedicated upscaler such as Topaz Gigapixel | Subscription; see our comparison | Your Mac | The deepest controls | Compared here |
| Smol | $29 once | Your Mac | Batch 2x, 3x, 4x next to your other compression | No model picker and no tuning controls |
If you only ever upscale, a dedicated tool is the more focused choice. Smol earns its place when the same app also compresses your gallery images, converts formats and compresses PDFs. Our best image compressor for Mac roundup covers that side.
When is Smol the wrong tool for upscaling?
Smol is the wrong tool in several cases, and you should know them before you buy.
- You need a factor above 4x. Smol offers 2x, 3x and 4x only.
- You want to repair a damaged or blurry photograph. See our old photo scans page for what Smol does and does not do there.
- You need a model picker or settings to tune how detail is rebuilt. Smol has none; it offers a factor and an output format.
- You are not on a Mac. Smol runs on macOS 13 or later (Apple Silicon) and macOS 14 or later (Intel) only.
- You need lossless output. Smol always re-encodes images when it compresses them.
Do I get a free trial?
No. There is no trial and purchases are not refundable. The homepage in-browser demo is not the app, so it will not show you the upscaler. Read the comparison page and weigh it before you buy.
Frequently asked questions
How do I upscale Midjourney images?
Download the render, drop it into an upscaler, and pick a factor. In Smol you choose 2x, 3x or 4x and an output format of PNG, JPG or WebP. First read your image width and divide the pixels your print needs by it to choose the factor.
What resolution do I need to print AI art?
Multiply the print size in inches by the DPI. Printful asks for at least 300 DPI on paper prints and 150 DPI on everything else. A 12 inch wide paper print at 300 DPI needs 3,600 pixels across. Check your printer’s own requirement before exporting.
Can I do a 4x upscale on a Mac without uploading anything?
Yes. Smol upscales 2x, 3x or 4x locally, so images never leave your Mac. It works on a single file or a folder, and writes PNG, JPG or WebP. It is a one-time $29 purchase for one Mac, with no credits.
Can I upscale Stable Diffusion images locally?
Yes. Any PNG or JPG from Stable Diffusion, ComfyUI or another generator can be dropped into Smol and enlarged 2x, 3x or 4x on your Mac. Nothing is uploaded, and your prompt and seed are not involved because the upscale runs on the finished file.
Does upscaling add detail to my AI image?
It adds pixels so a file meets a size requirement. Printify warns that you cannot add detail that was never there, and advises building the canvas large instead of upscaling a small web file. Always inspect the result at 100% before you print.
Should I export the upscaled image as PNG or JPG?
Use PNG for print masters, since Printful accepts PNG and JPG and requires PNG for DTG printing. Use JPG or WebP for web copies, and run Compress afterward to shrink them. Do not compress your print master without turning off the default resize.
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