Hi @Pixelmeplease, welcome to the forum! Wouter here, co-founder of Repper.
I understand your concern, and I can assure you it is possible to create high quality patterns with Repper. Indeed, once you know what to look out for, it gets pretty easy to achieve.
There are a bunch of things that come into play when it comes to resolution. I’ve discussed those in various places, but let me bring them together here, and you can see what info are the bits you’re looking for.
What happens from source image to pattern?
This article talks about how the resolution of your pattern is affected by the way it is generated. What comes into play here?
- The resolution of your source image (bigger = higher resolution)
- The size of the part of your source image you are repeating (bigger = high resolution)
- The tiling you are using (more complex tilings give you larger tiles, everything else being equal)
The article shows these points in much more detail.
Most importantly, no matter how large your source image, if your selection is very small, there are only so many pixels Repper has to work with. We aren’t doing any upsampling, though there are good AI upsampling services out there these days, if you need them.
Source image resolution and file size
You mentioned the upload limited of 15MB per image. Because we use JPEG and PNG (more efficient formats than TIFF or BMP), this will give you quite some bandwidth to upload large images. I myself often use images of 15-25 megapixels or more, no problem. In cases where your source images a very large, considering saving your source images at a JPEG quality of 90% or so. The impact on image quality is imperceivable but the reduction in file size is enormous. In terms of resolution, Repper can handle source images up to 12,000 x 12,000 pixels.
We’ve made an in-depth video about exporting patterns, which also has some pointers about how to optimize for resolution. Important here is to consider the DPI needs for your particular application (for example, textile will require lower resolution than paper, a poster less than a business card). Here’s a blogpost series I wrote about DPI, in case you’re interested.
What that looks like in practice
Let’s take the source image of our demo project, which is around 5,000x3,500 pixels. Let’s take a simple tiling (Octagon) and I select a very small part of the image. Below you can see, the resulting tile size is around 900 pixels (bottom left):
What does this mean for my resulting pattern? As I mentioned, I’ve made a whole series about how DPI works in general and specifically in Repper (you can find it here), but in short:
900 pixels / 300 DPI = 3 inches
Do you plan to use your pattern with a tile size no larger than 3 inches (7.5cm)? Perfect, you’re good to go! So for example, a print on a notebook with a few repeats would probably work great.
What if you’re printing on a bedspread? In this case, 150DPI would typically suffice, so now a single tile could already be 6 inches (or 15cm).
What if that’s not enough?
There are various things you can do:
- Make larger selections: 2x selection = 2x maximum tile size (Source images with less detail or elements lend themselves often better to selecting larger areas)
- If you have it, upload a larger version of the source image
- Use a more complex tile that creates a larger tile size
Below you can see a similar selection size leading to a much larger tile size of approximately 1,600 x 1,000 pixels when choosing a different tiling (here, Persian Star).
Below you see a larger source image (±6K x 4K = 24 megapixels) with a reasonably large selection and a medium-complexity tiling. The resulting tiling is over 2K x 4K, meaning the maximum printable height of a single tile (in red) at 300 DPI is over 13 inches or 30 cm. For fabric prints, you could go up to 60 cm.
I hope this helps! If you are having specific situations that you are struggling with that I have not mentioned here, please reply and I’ll try to address them specifically.