Guides for people who sell

Thirty-one guides, seven kinds of problem

Almost everything that goes wrong for a small seller happens at one of seven moments: preparing a file, photographing the thing, measuring a physical object, squeezing an export under somebody else's limit, working out what a sale actually leaves you, sending a parcel across a border, or waking up to a marketplace rule that changed while you slept. The thirty-one guides below are sorted into those seven moments. If you already know which one you are standing in, skip to it.

Preparing the file

Begin with DPI vs PPI if the vocabulary itself is the obstacle. It is the shortest guide here and it clears up the most expensive misunderstanding in the whole category — that the DPI number sitting in a file's metadata has no effect on how sharp the print comes out. What matters is pixels against physical inches, and there is exactly one bit of arithmetic to learn.

With that settled, Print-on-Demand Image Requirements gives the pixel dimensions Printful, Printify and Redbubble actually expect for each print area, plus the colour-mode and transparency rules that cause silent rejections. Etsy Image Sizes handles the shop side — listing photos, icon, cover, banner — and the automatic crops that quietly decapitate people in thumbnails. How to Make Seamless Patterns is the outlier of the group: a technique guide rather than a spec sheet, for anyone selling repeats on fabric, wrap or digital paper.

Three more sit underneath all of that. HEX, RGB and CMYK explains why HEX and RGB are the same number written two ways, why HSL is a rotation of it, and why CMYK is a different kind of thing entirely — which is the reason no single conversion to it is the correct one. Cricut & Silhouette File Formats is for anyone selling cut files: which formats Cricut Design Space and each Silhouette Studio edition will open, why Basic Edition refuses SVG, and the SVG features that get a file rejected. How ASCII Art Works is the one indulgence in the set — a single idea, brightness swapped for character density, plus the reason the output always comes out stretched.

Photographing the product

How to Shoot a Pure White Background starts where most listing photos fail: a camera will not hand you RGB 255,255,255 on its own, not even inside a lightbox, and getting there is a lighting, editing and cropping sequence rather than one slider. The arithmetic of the 85% fill is in there too. Why Cut-Out Product Photos Look Fake is the counterweight: six shadow errors, from products that float to shadows blurred evenly end to end to two light sources at once, each with the physics behind it and the fix.

The other two are about framing rather than light. Product Photo Safe Zones treats marketplace and social crops as arithmetic — what a centre crop keeps, what a square loses to each shape, and where the safe box actually lands. One Product Shoot, Every Feed moves that decision back to the tripod, where it belongs, so a single frame survives 1:1, 4:5, 2:3 and 9:16 without a reshoot.

Measuring the object

A wrap template or a placement chart is only as good as the three or four numbers you feed it, and those numbers are easy to take badly. How to Measure a Tumbler explains why a tapered cup unrolls into a fan rather than a rectangle — the reason so many wraps arrive with a wedge-shaped gap at the seam — and which three measurements decide the shape. T-Shirt Print Placement Measurements collects the widths, collar drops and per-size adjustments that print providers work to, so a design that looks centred on a medium does not ride up on a 3XL. Sticker Sizes for Die-Cut Printing covers bleed, safe border, die-cut versus kiss-cut, and the pixel counts each nominal size works out to at 300 DPI.

Standard Print & Frame Sizes is the reference the others keep pointing at: standard US frame sizes and the ISO A series in millimetres, inches and pixels, alongside the aspect ratios that decide how many of those sizes a single file can serve.

Exports with a hard limit

Sometimes the constraint is not taste but a number in somebody else's upload form. Fitting Print Files Under Etsy's 20 MB Download Limit works out how large a print file genuinely wants to be, identifies the multiplier that pushed yours past the five-files-of-20 MB allowance, and sets out what is safe to cut. Etsy Listing Video Export Settings does the same for motion: fifteen seconds and 100 MB imply a bitrate ceiling, and the arithmetic hands you the export settings that stay under it. Printing FNSKU Labels That Scan is the physical version of the same problem — a label that looks perfect on screen can still fail at the receiving desk, and there are five stages between file and scanner where it breaks, plus one test that catches it before a shipment does.

What the sale actually leaves you

Print on Demand Profit Margin is about the costs a per-order margin quietly ignores: sort every cost by what it scales with and a 31% headline turns into 12.8% of a real month. Why Your Etsy Payout Is Smaller Than Your Sales covers the gap between the two numbers that sellers notice first — the clock from sale to bank transfer, what a payment account reserve does to it, and why fees do not always come back with a refund. Digital Product License Terms reads a licence clause by clause, says what each clause actually does, and is candid about where a self-written one runs out of road. It is general information, not legal advice.

Crossing a border in 2026

This is the group that changed the most, and the group with real money attached. If you ship to the United States, Pricing for the US After DDP Became Mandatory is the one to read first: the $800 de minimis exemption is gone and duty is now yours to collect at checkout, which means your old price was built on an assumption that no longer holds. US Mail Imports Under $2,500 is the operational sequel — who files the entry, with which HTSUS codes, and by when.

For the European Union, The EU's €3 Parcel Duty matters most for mixed parcels, because the charge lands per tariff classification rather than per item: five identical t-shirts cost you once, three t-shirts and a watch cost you twice. The EU Parcel Handling Fee is the companion to it, and deliberately answers less: a second charge was agreed in March 2026 with a 1 November deadline attached, but the amount has still not been set, so that page tracks what is settled rather than pretending to a number. EU Packaging EPR: The Marketplace Check is a listing-permission problem rather than a shipping one — from August 2026 a marketplace has to hold your EPR number for the buyer's country before your listing can go live there. What Has to Go on a GPSR Label is the oldest rule in this section and the one most often discovered late, usually when a listing is already suspended.

Three more EU rules land on the product itself rather than on the parcel, and each is badly served by the coverage around it. EU Battery Removability 2027 is written about phones almost everywhere, which is no help if what you sell is earbuds, fairy lights or a toy — so that page gives a verdict per product type instead, including the two categories that turn out to sit outside the rule entirely. EUDR Deadline 2026 exists mainly to correct a date: a lot of published guidance still runs on 30 June 2026, which belonged to a postponement that was itself replaced in December 2025. AI Product Images and the EU AI Act takes apart the claim that every AI-assisted listing photo now needs a visible AI badge, by reading Article 50 according to which actor each paragraph names.

When the marketplace moves the goalposts

Platform rules deserve their own category, because they arrive with a deadline and no negotiation. Amazon's 75-Character Title Limit walks through what happens on 27 July 2026, where the words you cut are supposed to go instead, and what Amazon does to titles that are still over the limit when the date passes. After Amazon's Title Cap picks up on the other side of that date: the new Item Highlights field, what the automatic rewrite moves where, which permission decides whether you ever see it coming, and the handful of questions Amazon was asked and did not answer.

Amazon Listing Character Limits takes the wider view, and takes it sceptically: the published tables of Amazon's field limits disagree with one another, so it separates the numbers that are actually verifiable from the ones that are folklore, and shows you how to read your own. Etsy SEO Myths does the equivalent on the other platform — ten familiar pieces of tag and title advice checked one at a time against what Etsy's own Seller Handbook and Help Centre say, four of which are costing you tag slots.